CML-CML level shifter...

[John Larkin]

I have a differential output from a fast CML flipflop, powered by +3
and ground, and want to drive another CML-input part. If the load
gadget was also powered from +3, I\'d just connect them with a couple
of 50 ohm traces. But the Vcc of the destination part could be
anything from +3 to -2.

I want full speed and DC coupling, so the ideal part to put in series
with both runs is a battery of the appropriate voltage, namely the
difference in supply voltages. Couldn\'t find anything that would work
like that.

This thing below sorta fakes the batteries. It seems to work. The
constraints on the CML transmitter (how far can the pins actually
swing?) and on the receiver device (how far can the pins actually
swing?) are far from clear, so we\'ll have to test this some.

This looks pretty simple, but took a lot of thinking and many stupid
simulations to get it to be simple. It bothered me enough to keep at
it. Can\'t ski... too much snow.



Version 4
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WINDOW 0 -64 41 Left 2
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SYMATTR Value PULSE(16m 0 1u 5n 1n 100u)
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TEXT -64 560 Left 2 ;CML Flop
TEXT 800 560 Left 2 ;CML Load
TEXT 264 504 Left 3 ;CML-CML Level Shifter
TEXT 328 616 Left 2 !.tran 0 200u 0
TEXT 320 560 Left 2 ;JL Dec 24 2021
TEXT 896 272 Left 2 ;+3 to -2
RECTANGLE Normal 176 1120 -224 -32 2
RECTANGLE Normal 1040 1120 640 -32 2


--

If a man will begin with certainties, he shall end with doubts,
but if he will be content to begin with doubts he shall end in certainties.
Francis Bacon

 

[whit3rd]

On Friday, December 24, 2021 at 2:21:29 PM UTC-8, John Larkin wrote:

I have a differential output from a fast CML flipflop, powered by +3
and ground, and want to drive another CML-input part. If the load
gadget was also powered from +3, I\'d just connect them with a couple
of 50 ohm traces. But the Vcc of the destination part could be
anything from +3 to -2.

I want full speed and DC coupling, so the ideal part to put in series
with both runs is a battery of the appropriate voltage,

So, do that. Just a capacitor, obviously, won\'t have the constant DC step
if there\'s any low frequencies present, but you can put a three-transistor
current mirror dual-source on the most positive rail, and another three-transistor
current mirror dual-sink on the most negative rail, and connect the input
transistors\' bases of those mirrors with the appropriate resistor to make
a constant-current bias. Then, instead of coupling capacitor alone, you
put a bit of bypass resistor across each capacitor, and feed the high terminal
with one source, and the low terminal with one sink (and \'cuz it\'s differential, you\'d
have the second source and sink for the other half\'s capacitor).

As long as you don\'t dial the current up beyond what the CML sources , it\'ll drive
a lot like a battery in series. If the HF gets too much Miller effect, a few ferrite beads
can help, obviously.

You do have to know polarity of the offset required at wiring-time,
but the mirrors\' emitter supplies are places you can apply
dynamic controls of the amplitude and range of offset.

 

[server]

On Fri, 24 Dec 2021 20:47:01 -0800 (PST), whit3rd <whit3rd@gmail.com>
wrote:

On Friday, December 24, 2021 at 2:21:29 PM UTC-8, John Larkin wrote:
I have a differential output from a fast CML flipflop, powered by +3
and ground, and want to drive another CML-input part. If the load
gadget was also powered from +3, I\'d just connect them with a couple
of 50 ohm traces. But the Vcc of the destination part could be
anything from +3 to -2.

I want full speed and DC coupling, so the ideal part to put in series
with both runs is a battery of the appropriate voltage,

So, do that. Just a capacitor, obviously, won\'t have the constant DC step
if there\'s any low frequencies present, but you can put a three-transistor
current mirror dual-source on the most positive rail, and another three-transistor
current mirror dual-sink on the most negative rail, and connect the input
transistors\' bases of those mirrors with the appropriate resistor to make
a constant-current bias. Then, instead of coupling capacitor alone, you
put a bit of bypass resistor across each capacitor, and feed the high terminal
with one source, and the low terminal with one sink (and \'cuz it\'s differential, you\'d
have the second source and sink for the other half\'s capacitor).

As long as you don\'t dial the current up beyond what the CML sources , it\'ll drive
a lot like a battery in series. If the HF gets too much Miller effect, a few ferrite beads
can help, obviously.

You do have to know polarity of the offset required at wiring-time,
but the mirrors\' emitter supplies are places you can apply
dynamic controls of the amplitude and range of offset.

The polarity can go either way, which sure doesn\'t help.

In this case, I want to couple logic levels with features from maybe
50 ps to 50 years. I might grudgingly allow the two traces between
chips to be half an inch long, with one sideways cap in the middle of
each. That\'s no place for a dozen transistors or ICs. My circuit
started as two floating programmable voltages across the coupling
caps, and stepwise deteriorated to the simple thing I have now. The
big resistors fake dueling current sources, and the dropping resistor
across the cap turns out to work at infinite ohms.

There is a more general issue of splitting a signal into a number of
bandwidths, transmitting, and then recombining neatly. Phil Hobbs
recently needed to drive a ganfet gate with a fast-edge fairly long
pulse, when the fet is riding hundreds of volts off ground. I don\'t
know how he wound up doing that. In audio, a crossover has similar
issues, bandwidth splitting.

You can buy logic isolator chips, some with isolated power, but they
are terrible for fast stuff. I\'ve many times combined a fast (cap or
transformer) AC path with a slow optocoupler.

There are megabuck class oscilloscopes that split signals onto
multiple paths of different bandwidths (with mixers I think) and then
digitize and recombine with lots of DSP. That\'s the deconvolution
problem.

The general problem of bandwidth splitting and combining keeps popping
up. It\'s worth a long paper or a short book. This is a good start:

https://www.dropbox.com/s/ct7x6449fjz5d4q/RL-RC.jpg?raw=1



--

I yam what I yam - Popeye

 

[Phil Hobbs]

jlarkin@highlandsniptechnology.com wrote:

On Fri, 24 Dec 2021 20:47:01 -0800 (PST), whit3rd <whit3rd@gmail.com
wrote:

On Friday, December 24, 2021 at 2:21:29 PM UTC-8, John Larkin wrote:
I have a differential output from a fast CML flipflop, powered by +3
and ground, and want to drive another CML-input part. If the load
gadget was also powered from +3, I\'d just connect them with a couple
of 50 ohm traces. But the Vcc of the destination part could be
anything from +3 to -2.

I want full speed and DC coupling, so the ideal part to put in series
with both runs is a battery of the appropriate voltage,

So, do that. Just a capacitor, obviously, won\'t have the constant DC step
if there\'s any low frequencies present, but you can put a three-transistor
current mirror dual-source on the most positive rail, and another three-transistor
current mirror dual-sink on the most negative rail, and connect the input
transistors\' bases of those mirrors with the appropriate resistor to make
a constant-current bias. Then, instead of coupling capacitor alone, you
put a bit of bypass resistor across each capacitor, and feed the high terminal
with one source, and the low terminal with one sink (and \'cuz it\'s differential, you\'d
have the second source and sink for the other half\'s capacitor).

As long as you don\'t dial the current up beyond what the CML sources , it\'ll drive
a lot like a battery in series. If the HF gets too much Miller effect, a few ferrite beads
can help, obviously.

You do have to know polarity of the offset required at wiring-time,
but the mirrors\' emitter supplies are places you can apply
dynamic controls of the amplitude and range of offset.

The polarity can go either way, which sure doesn\'t help.

In this case, I want to couple logic levels with features from maybe
50 ps to 50 years. I might grudgingly allow the two traces between
chips to be half an inch long, with one sideways cap in the middle of
each. That\'s no place for a dozen transistors or ICs. My circuit
started as two floating programmable voltages across the coupling
caps, and stepwise deteriorated to the simple thing I have now. The
big resistors fake dueling current sources, and the dropping resistor
across the cap turns out to work at infinite ohms.

There is a more general issue of splitting a signal into a number of
bandwidths, transmitting, and then recombining neatly. Phil Hobbs
recently needed to drive a ganfet gate with a fast-edge fairly long
pulse, when the fet is riding hundreds of volts off ground. I don\'t
know how he wound up doing that.

Hasn\'t been implemented yet. Probably something like this:
<https://electrooptical.net/www/sed/IsolatedGaN.zip>.

The Coilcraft transformer is way too clunky, so it\'ll either be an RC or
a much lighter-weight transformer--maybe one of your
coax-jumper-plus-potcore things. (The switch has to ride on top of a
-450V avalanche photodiode bias supply.)

The common-gate FET is an interesting idea I found in an app note, of
all places. (I assume that means it\'s old hat, but I hadn\'t seen it
before.)

The substrate diode conducts in one direction and the transistor action
in the other, so the hold time is limited by the RC and not the
voltseconds of the transformer. It also allows extending the hold time
indefinitely by pulsing the gate driver.

In audio, a crossover has similar
issues, bandwidth splitting.

You can buy logic isolator chips, some with isolated power, but they
are terrible for fast stuff. I\'ve many times combined a fast (cap or
transformer) AC path with a slow optocoupler.

There are megabuck class oscilloscopes that split signals onto
multiple paths of different bandwidths (with mixers I think) and then
digitize and recombine with lots of DSP. That\'s the deconvolution
problem.

The general problem of bandwidth splitting and combining keeps popping
up. It\'s worth a long paper or a short book. This is a good start:

https://www.dropbox.com/s/ct7x6449fjz5d4q/RL-RC.jpg?raw=1

I\'d like to read that book!

The Tektronix \'feedbeside\' thing requires really good matching between
branches to get better than oscilloscope accuracy.

If the matching isn\'t very close, you wind up with low-frequency
pole/zero pairs that don\'t quite cancel. That leads to settling
whoopdedoos at late times, which are often super obnoxious in real
applications but which will be quite invisible on a scope.

Cheers

Phil Hobbs


--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[server]

On Sat, 25 Dec 2021 17:57:39 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

jlarkin@highlandsniptechnology.com wrote:
On Fri, 24 Dec 2021 20:47:01 -0800 (PST), whit3rd <whit3rd@gmail.com
wrote:

On Friday, December 24, 2021 at 2:21:29 PM UTC-8, John Larkin wrote:
I have a differential output from a fast CML flipflop, powered by +3
and ground, and want to drive another CML-input part. If the load
gadget was also powered from +3, I\'d just connect them with a couple
of 50 ohm traces. But the Vcc of the destination part could be
anything from +3 to -2.

I want full speed and DC coupling, so the ideal part to put in series
with both runs is a battery of the appropriate voltage,

So, do that. Just a capacitor, obviously, won\'t have the constant DC step
if there\'s any low frequencies present, but you can put a three-transistor
current mirror dual-source on the most positive rail, and another three-transistor
current mirror dual-sink on the most negative rail, and connect the input
transistors\' bases of those mirrors with the appropriate resistor to make
a constant-current bias. Then, instead of coupling capacitor alone, you
put a bit of bypass resistor across each capacitor, and feed the high terminal
with one source, and the low terminal with one sink (and \'cuz it\'s differential, you\'d
have the second source and sink for the other half\'s capacitor).

As long as you don\'t dial the current up beyond what the CML sources , it\'ll drive
a lot like a battery in series. If the HF gets too much Miller effect, a few ferrite beads
can help, obviously.

You do have to know polarity of the offset required at wiring-time,
but the mirrors\' emitter supplies are places you can apply
dynamic controls of the amplitude and range of offset.

The polarity can go either way, which sure doesn\'t help.

In this case, I want to couple logic levels with features from maybe
50 ps to 50 years. I might grudgingly allow the two traces between
chips to be half an inch long, with one sideways cap in the middle of
each. That\'s no place for a dozen transistors or ICs. My circuit
started as two floating programmable voltages across the coupling
caps, and stepwise deteriorated to the simple thing I have now. The
big resistors fake dueling current sources, and the dropping resistor
across the cap turns out to work at infinite ohms.

There is a more general issue of splitting a signal into a number of
bandwidths, transmitting, and then recombining neatly. Phil Hobbs
recently needed to drive a ganfet gate with a fast-edge fairly long
pulse, when the fet is riding hundreds of volts off ground. I don\'t
know how he wound up doing that.

Hasn\'t been implemented yet. Probably something like this:
https://electrooptical.net/www/sed/IsolatedGaN.zip>.

The Coilcraft transformer is way too clunky, so it\'ll either be an RC or
a much lighter-weight transformer--maybe one of your
coax-jumper-plus-potcore things. (The switch has to ride on top of a
-450V avalanche photodiode bias supply.)

The common-gate FET is an interesting idea I found in an app note, of
all places. (I assume that means it\'s old hat, but I hadn\'t seen it
before.)

The substrate diode conducts in one direction and the transistor action
in the other, so the hold time is limited by the RC and not the
voltseconds of the transformer. It also allows extending the hold time
indefinitely by pulsing the gate driver.

In audio, a crossover has similar
issues, bandwidth splitting.

You can buy logic isolator chips, some with isolated power, but they
are terrible for fast stuff. I\'ve many times combined a fast (cap or
transformer) AC path with a slow optocoupler.

There are megabuck class oscilloscopes that split signals onto
multiple paths of different bandwidths (with mixers I think) and then
digitize and recombine with lots of DSP. That\'s the deconvolution
problem.

The general problem of bandwidth splitting and combining keeps popping
up. It\'s worth a long paper or a short book. This is a good start:

https://www.dropbox.com/s/ct7x6449fjz5d4q/RL-RC.jpg?raw=1

I\'d like to read that book!

The Tektronix \'feedbeside\' thing requires really good matching between
branches to get better than oscilloscope accuracy.

If the matching isn\'t very close, you wind up with low-frequency
pole/zero pairs that don\'t quite cancel. That leads to settling
whoopdedoos at late times, which are often super obnoxious in real
applications but which will be quite invisible on a scope.

The equivalent of p/z mismatch is a problem even in logic couplers.
The trick is to keep the corner freqs far apart. The AC path should
have a much longer time constant than the maintaining DC path. A bit
of clamping helps too.

Cheers

Phil Hobbs

When Tek did the 7104 1 GHz microchannel scope, they considered
splitting the gain path into bandwidth zones, amplifying, and
combining. But linear ICs got good enough about that time, so they
used them.



--

I yam what I yam - Popeye

 

[Phil Hobbs]

jlarkin@highlandsniptechnology.com wrote:

On Sat, 25 Dec 2021 17:57:39 -0500, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

jlarkin@highlandsniptechnology.com wrote:
On Fri, 24 Dec 2021 20:47:01 -0800 (PST), whit3rd <whit3rd@gmail.com
wrote:

On Friday, December 24, 2021 at 2:21:29 PM UTC-8, John Larkin wrote:
I have a differential output from a fast CML flipflop, powered by +3
and ground, and want to drive another CML-input part. If the load
gadget was also powered from +3, I\'d just connect them with a couple
of 50 ohm traces. But the Vcc of the destination part could be
anything from +3 to -2.

I want full speed and DC coupling, so the ideal part to put in series
with both runs is a battery of the appropriate voltage,

So, do that. Just a capacitor, obviously, won\'t have the constant DC step
if there\'s any low frequencies present, but you can put a three-transistor
current mirror dual-source on the most positive rail, and another three-transistor
current mirror dual-sink on the most negative rail, and connect the input
transistors\' bases of those mirrors with the appropriate resistor to make
a constant-current bias. Then, instead of coupling capacitor alone, you
put a bit of bypass resistor across each capacitor, and feed the high terminal
with one source, and the low terminal with one sink (and \'cuz it\'s differential, you\'d
have the second source and sink for the other half\'s capacitor).

As long as you don\'t dial the current up beyond what the CML sources , it\'ll drive
a lot like a battery in series. If the HF gets too much Miller effect, a few ferrite beads
can help, obviously.

You do have to know polarity of the offset required at wiring-time,
but the mirrors\' emitter supplies are places you can apply
dynamic controls of the amplitude and range of offset.

The polarity can go either way, which sure doesn\'t help.

In this case, I want to couple logic levels with features from maybe
50 ps to 50 years. I might grudgingly allow the two traces between
chips to be half an inch long, with one sideways cap in the middle of
each. That\'s no place for a dozen transistors or ICs. My circuit
started as two floating programmable voltages across the coupling
caps, and stepwise deteriorated to the simple thing I have now. The
big resistors fake dueling current sources, and the dropping resistor
across the cap turns out to work at infinite ohms.

There is a more general issue of splitting a signal into a number of
bandwidths, transmitting, and then recombining neatly. Phil Hobbs
recently needed to drive a ganfet gate with a fast-edge fairly long
pulse, when the fet is riding hundreds of volts off ground. I don\'t
know how he wound up doing that.

Hasn\'t been implemented yet. Probably something like this:
https://electrooptical.net/www/sed/IsolatedGaN.zip>.

The Coilcraft transformer is way too clunky, so it\'ll either be an RC or
a much lighter-weight transformer--maybe one of your
coax-jumper-plus-potcore things. (The switch has to ride on top of a
-450V avalanche photodiode bias supply.)

The common-gate FET is an interesting idea I found in an app note, of
all places. (I assume that means it\'s old hat, but I hadn\'t seen it
before.)

The substrate diode conducts in one direction and the transistor action
in the other, so the hold time is limited by the RC and not the
voltseconds of the transformer. It also allows extending the hold time
indefinitely by pulsing the gate driver.

In audio, a crossover has similar
issues, bandwidth splitting.

You can buy logic isolator chips, some with isolated power, but they
are terrible for fast stuff. I\'ve many times combined a fast (cap or
transformer) AC path with a slow optocoupler.

There are megabuck class oscilloscopes that split signals onto
multiple paths of different bandwidths (with mixers I think) and then
digitize and recombine with lots of DSP. That\'s the deconvolution
problem.

The general problem of bandwidth splitting and combining keeps popping
up. It\'s worth a long paper or a short book. This is a good start:

https://www.dropbox.com/s/ct7x6449fjz5d4q/RL-RC.jpg?raw=1

I\'d like to read that book!

The Tektronix \'feedbeside\' thing requires really good matching between
branches to get better than oscilloscope accuracy.

If the matching isn\'t very close, you wind up with low-frequency
pole/zero pairs that don\'t quite cancel. That leads to settling
whoopdedoos at late times, which are often super obnoxious in real
applications but which will be quite invisible on a scope.

The equivalent of p/z mismatch is a problem even in logic couplers.
The trick is to keep the corner freqs far apart. The AC path should
have a much longer time constant than the maintaining DC path. A bit
of clamping helps too.

I\'m not sure that works in general, though--you\'d need one feedback loop
to govern the other, and you always wind up with problems where they
change roles. Making the AC time constant slow just exports the problem
to late times. Some applications don\'t care, in which case that\'s a big
win, but some do.

Cheers

Phil Hobbs

PS: Merry Christmas!

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[server]

On Sat, 25 Dec 2021 19:46:38 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

jlarkin@highlandsniptechnology.com wrote:
On Sat, 25 Dec 2021 17:57:39 -0500, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

jlarkin@highlandsniptechnology.com wrote:
On Fri, 24 Dec 2021 20:47:01 -0800 (PST), whit3rd <whit3rd@gmail.com
wrote:

On Friday, December 24, 2021 at 2:21:29 PM UTC-8, John Larkin wrote:
I have a differential output from a fast CML flipflop, powered by +3
and ground, and want to drive another CML-input part. If the load
gadget was also powered from +3, I\'d just connect them with a couple
of 50 ohm traces. But the Vcc of the destination part could be
anything from +3 to -2.

I want full speed and DC coupling, so the ideal part to put in series
with both runs is a battery of the appropriate voltage,

So, do that. Just a capacitor, obviously, won\'t have the constant DC step
if there\'s any low frequencies present, but you can put a three-transistor
current mirror dual-source on the most positive rail, and another three-transistor
current mirror dual-sink on the most negative rail, and connect the input
transistors\' bases of those mirrors with the appropriate resistor to make
a constant-current bias. Then, instead of coupling capacitor alone, you
put a bit of bypass resistor across each capacitor, and feed the high terminal
with one source, and the low terminal with one sink (and \'cuz it\'s differential, you\'d
have the second source and sink for the other half\'s capacitor).

As long as you don\'t dial the current up beyond what the CML sources , it\'ll drive
a lot like a battery in series. If the HF gets too much Miller effect, a few ferrite beads
can help, obviously.

You do have to know polarity of the offset required at wiring-time,
but the mirrors\' emitter supplies are places you can apply
dynamic controls of the amplitude and range of offset.

The polarity can go either way, which sure doesn\'t help.

In this case, I want to couple logic levels with features from maybe
50 ps to 50 years. I might grudgingly allow the two traces between
chips to be half an inch long, with one sideways cap in the middle of
each. That\'s no place for a dozen transistors or ICs. My circuit
started as two floating programmable voltages across the coupling
caps, and stepwise deteriorated to the simple thing I have now. The
big resistors fake dueling current sources, and the dropping resistor
across the cap turns out to work at infinite ohms.

There is a more general issue of splitting a signal into a number of
bandwidths, transmitting, and then recombining neatly. Phil Hobbs
recently needed to drive a ganfet gate with a fast-edge fairly long
pulse, when the fet is riding hundreds of volts off ground. I don\'t
know how he wound up doing that.

Hasn\'t been implemented yet. Probably something like this:
https://electrooptical.net/www/sed/IsolatedGaN.zip>.

The Coilcraft transformer is way too clunky, so it\'ll either be an RC or
a much lighter-weight transformer--maybe one of your
coax-jumper-plus-potcore things. (The switch has to ride on top of a
-450V avalanche photodiode bias supply.)

The common-gate FET is an interesting idea I found in an app note, of
all places. (I assume that means it\'s old hat, but I hadn\'t seen it
before.)

The substrate diode conducts in one direction and the transistor action
in the other, so the hold time is limited by the RC and not the
voltseconds of the transformer. It also allows extending the hold time
indefinitely by pulsing the gate driver.

In audio, a crossover has similar
issues, bandwidth splitting.

You can buy logic isolator chips, some with isolated power, but they
are terrible for fast stuff. I\'ve many times combined a fast (cap or
transformer) AC path with a slow optocoupler.

There are megabuck class oscilloscopes that split signals onto
multiple paths of different bandwidths (with mixers I think) and then
digitize and recombine with lots of DSP. That\'s the deconvolution
problem.

The general problem of bandwidth splitting and combining keeps popping
up. It\'s worth a long paper or a short book. This is a good start:

https://www.dropbox.com/s/ct7x6449fjz5d4q/RL-RC.jpg?raw=1

I\'d like to read that book!

The Tektronix \'feedbeside\' thing requires really good matching between
branches to get better than oscilloscope accuracy.

If the matching isn\'t very close, you wind up with low-frequency
pole/zero pairs that don\'t quite cancel. That leads to settling
whoopdedoos at late times, which are often super obnoxious in real
applications but which will be quite invisible on a scope.

The equivalent of p/z mismatch is a problem even in logic couplers.
The trick is to keep the corner freqs far apart. The AC path should
have a much longer time constant than the maintaining DC path. A bit
of clamping helps too.

I\'m not sure that works in general, though--you\'d need one feedback loop
to govern the other, and you always wind up with problems where they
change roles. Making the AC time constant slow just exports the problem
to late times. Some applications don\'t care, in which case that\'s a big
win, but some do.

Cheers

Phil Hobbs

PS: Merry Christmas!

I got a beautiful set of razor sharp Wusthof knives. They slice
through Tartine sourdough like a chain saw. Pay no mind to the
band-aids.

I got Mo a 48\" Sony oled TV. It\'s astonishing. It makes the old LCD
look washed-out and fuzzy.



--

I yam what I yam - Popeye

 

[whit3rd]

On Saturday, December 25, 2021 at 7:12:18 AM UTC-8, jla...@highlandsniptechnology.com wrote:

On Fri, 24 Dec 2021 20:47:01 -0800 (PST), whit3rd <whi...@gmail.com
wrote:
On Friday, December 24, 2021 at 2:21:29 PM UTC-8, John Larkin wrote:
I have a differential output from a fast CML flipflop, powered by +3
and ground, and want to drive another CML-input part. If the load
gadget was also powered from +3, I\'d just connect them with a couple
of 50 ohm traces. But the Vcc of the destination part could be
anything from +3 to -2.

I want full speed and DC coupling, so the ideal part to put in series
with both runs is a battery of the appropriate voltage,

So, do that. Just a capacitor, obviously, won\'t have the constant DC step
if there\'s any low frequencies present, but you can put a three-transistor
current mirror dual-source on the most positive rail, and...

The polarity can go either way, which sure doesn\'t help.

In this case, I want to couple logic levels with features from maybe
50 ps to 50 years. I might grudgingly allow the two traces between
chips to be half an inch long, with one sideways cap in the middle of
each. That\'s no place for a dozen transistors or ICs.

It only has one resistor and capacitor in each signal wire,
that other circuitry is just the power supply, carries (ideally)
none of the HF signal; ferrites for blocking are... tiny, if required.

The resistor could piggyback on the capacitor, if space is that tight...

The general problem of bandwidth splitting and combining keeps popping
up. It\'s worth a long paper or a short book.

Oh, there\'s a lot of interesting problems; howzabout an injectable
circular transmission line, so you can insert a transient signal and keep recirculating
the signal past a refresh amplifier/sampler until those golden nanoseconds
have had all the picoseconds nailed down in memory? You can\'t quite
do that with a cyclotron, the electrons DO revisit regularly, but
injection is always in tiny bunches...

Some of the inline amplifiers for optical fiber are suggestive, though.

 

[server]

On Sun, 26 Dec 2021 02:34:39 -0800 (PST), whit3rd <whit3rd@gmail.com>
wrote:

On Saturday, December 25, 2021 at 7:12:18 AM UTC-8, jla...@highlandsniptechnology.com wrote:
On Fri, 24 Dec 2021 20:47:01 -0800 (PST), whit3rd <whi...@gmail.com
wrote:
On Friday, December 24, 2021 at 2:21:29 PM UTC-8, John Larkin wrote:
I have a differential output from a fast CML flipflop, powered by +3
and ground, and want to drive another CML-input part. If the load
gadget was also powered from +3, I\'d just connect them with a couple
of 50 ohm traces. But the Vcc of the destination part could be
anything from +3 to -2.

I want full speed and DC coupling, so the ideal part to put in series
with both runs is a battery of the appropriate voltage,

So, do that. Just a capacitor, obviously, won\'t have the constant DC step
if there\'s any low frequencies present, but you can put a three-transistor
current mirror dual-source on the most positive rail, and...

The polarity can go either way, which sure doesn\'t help.

In this case, I want to couple logic levels with features from maybe
50 ps to 50 years. I might grudgingly allow the two traces between
chips to be half an inch long, with one sideways cap in the middle of
each. That\'s no place for a dozen transistors or ICs.

It only has one resistor and capacitor in each signal wire,
that other circuitry is just the power supply, carries (ideally)
none of the HF signal; ferrites for blocking are... tiny, if required.

The resistor could piggyback on the capacitor, if space is that tight...

Got a schematic or a sim?

The general problem of bandwidth splitting and combining keeps popping
up. It\'s worth a long paper or a short book.

Oh, there\'s a lot of interesting problems; howzabout an injectable
circular transmission line, so you can insert a transient signal and keep recirculating
the signal past a refresh amplifier/sampler until those golden nanoseconds
have had all the picoseconds nailed down in memory? You can\'t quite
do that with a cyclotron, the electrons DO revisit regularly, but
injection is always in tiny bunches...

We have considered a circular parametric oscillator as a breed of
triggered oscillator, which would be cute but complex.

Some of the inline amplifiers for optical fiber are suggestive, though.

--

I yam what I yam - Popeye

 

[server]

On Sat, 25 Dec 2021 17:57:39 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

jlarkin@highlandsniptechnology.com wrote:
On Fri, 24 Dec 2021 20:47:01 -0800 (PST), whit3rd <whit3rd@gmail.com
wrote:

On Friday, December 24, 2021 at 2:21:29 PM UTC-8, John Larkin wrote:
I have a differential output from a fast CML flipflop, powered by +3
and ground, and want to drive another CML-input part. If the load
gadget was also powered from +3, I\'d just connect them with a couple
of 50 ohm traces. But the Vcc of the destination part could be
anything from +3 to -2.

I want full speed and DC coupling, so the ideal part to put in series
with both runs is a battery of the appropriate voltage,

So, do that. Just a capacitor, obviously, won\'t have the constant DC step
if there\'s any low frequencies present, but you can put a three-transistor
current mirror dual-source on the most positive rail, and another three-transistor
current mirror dual-sink on the most negative rail, and connect the input
transistors\' bases of those mirrors with the appropriate resistor to make
a constant-current bias. Then, instead of coupling capacitor alone, you
put a bit of bypass resistor across each capacitor, and feed the high terminal
with one source, and the low terminal with one sink (and \'cuz it\'s differential, you\'d
have the second source and sink for the other half\'s capacitor).

As long as you don\'t dial the current up beyond what the CML sources , it\'ll drive
a lot like a battery in series. If the HF gets too much Miller effect, a few ferrite beads
can help, obviously.

You do have to know polarity of the offset required at wiring-time,
but the mirrors\' emitter supplies are places you can apply
dynamic controls of the amplitude and range of offset.

The polarity can go either way, which sure doesn\'t help.

In this case, I want to couple logic levels with features from maybe
50 ps to 50 years. I might grudgingly allow the two traces between
chips to be half an inch long, with one sideways cap in the middle of
each. That\'s no place for a dozen transistors or ICs. My circuit
started as two floating programmable voltages across the coupling
caps, and stepwise deteriorated to the simple thing I have now. The
big resistors fake dueling current sources, and the dropping resistor
across the cap turns out to work at infinite ohms.

There is a more general issue of splitting a signal into a number of
bandwidths, transmitting, and then recombining neatly. Phil Hobbs
recently needed to drive a ganfet gate with a fast-edge fairly long
pulse, when the fet is riding hundreds of volts off ground. I don\'t
know how he wound up doing that.

Hasn\'t been implemented yet. Probably something like this:
https://electrooptical.net/www/sed/IsolatedGaN.zip>.

The Coilcraft transformer is way too clunky, so it\'ll either be an RC or
a much lighter-weight transformer--maybe one of your
coax-jumper-plus-potcore things. (The switch has to ride on top of a
-450V avalanche photodiode bias supply.)

You could maybe use a memory element on the high side, a flipflop or a
schmitt trigger or maybe even just a capacitor, and drive it from
narrow positive and negative spikes through a transformer. That could
be done with zero static power required on the high side.

The non-inverting schmitt case has analogies to my pulse coupler. Cap
to the schmitt input, feedback resistor to sustain. Might work.



--

I yam what I yam - Popeye

 

[Joe Gwinn]

On Sat, 25 Dec 2021 21:33:00 -0800, jlarkin@highlandsniptechnology.com
wrote:

[snip]

I got a beautiful set of razor sharp Wusthof knives. They slice
through Tartine sourdough like a chain saw. Pay no mind to the
band-aids.

Yeah. They will dull gradually, and need whetting from time to time.
What I use is a Norton double-grit waterstone and a very solid
adjustable rubber clamp base so the stone doesn\'t slide around and/or
damage the countertops.

..<https://www.amazon.com/dp/B0006NFDOY?psc=1&ref=ppx_pop_dt_b_product_details>

..<https://www.amazon.com/dp/B00NFB2MTI?psc=1&ref=ppx_pop_dt_b_product_details>

I just gave this set to a family member whose knives were essentially
useless. I did the initial sharpening on two of them, and people were
astonished at the difference, even though those blades were made of
very soft steel. (Unlike Wusthof).

She will also be getting a polyethylene cutting board - she used to
cut on ceramic plates, ruining both plate and knife.

I got Mo a 48\" Sony oled TV. It\'s astonishing. It makes the old LCD
look washed-out and fuzzy.

I got a 48\" Sony for my wife a few years ago, with full HD (had to
upgrade COMCAST service as well). The improvement was stunning,
especially for baseball and football (US) games. She also likes to
watch French movies on Netflix, to improve her French.

Joe Gwinn

 

[server]

On Sun, 26 Dec 2021 12:37:54 -0500, Joe Gwinn <joegwinn@comcast.net>
wrote:

On Sat, 25 Dec 2021 21:33:00 -0800, jlarkin@highlandsniptechnology.com
wrote:

[snip]

I got a beautiful set of razor sharp Wusthof knives. They slice
through Tartine sourdough like a chain saw. Pay no mind to the
band-aids.

Yeah. They will dull gradually, and need whetting from time to time.
What I use is a Norton double-grit waterstone and a very solid
adjustable rubber clamp base so the stone doesn\'t slide around and/or
damage the countertops.

.<https://www.amazon.com/dp/B0006NFDOY?psc=1&ref=ppx_pop_dt_b_product_details

.<https://www.amazon.com/dp/B00NFB2MTI?psc=1&ref=ppx_pop_dt_b_product_details

I just gave this set to a family member whose knives were essentially
useless. I did the initial sharpening on two of them, and people were
astonished at the difference, even though those blades were made of
very soft steel. (Unlike Wusthof).

She will also be getting a polyethylene cutting board - she used to
cut on ceramic plates, ruining both plate and knife.


I got Mo a 48\" Sony oled TV. It\'s astonishing. It makes the old LCD
look washed-out and fuzzy.

I got a 48\" Sony for my wife a few years ago, with full HD (had to
upgrade COMCAST service as well). The improvement was stunning,
especially for baseball and football (US) games. She also likes to
watch French movies on Netflix, to improve her French.

Joe Gwinn

I\'m looking forward to more OLEDs in instruments. They are bright,
sharp, color saturated, and have great viewing angles.

Comcast gets maligned a lot, but they have been great for us. They
keep upgrading speed and video quality to be competitive. I\'m now
getting 130+40 mbps on the basic plan, which is about as fast as
anyone needs.

The pattern is that bandwidth is essentially free to the providers, so
if you complain about anything they upgrade your speed to appease you.
Both Comcast and Suddenlink did that for us when we had a complaint.



--

I yam what I yam - Popeye

 

[Joe Gwinn]

On Sun, 26 Dec 2021 09:55:34 -0800, jlarkin@highlandsniptechnology.com
wrote:

On Sun, 26 Dec 2021 12:37:54 -0500, Joe Gwinn <joegwinn@comcast.net
wrote:

On Sat, 25 Dec 2021 21:33:00 -0800, jlarkin@highlandsniptechnology.com
wrote:

[snip]

I got a beautiful set of razor sharp Wusthof knives. They slice
through Tartine sourdough like a chain saw. Pay no mind to the
band-aids.

Yeah. They will dull gradually, and need whetting from time to time.
What I use is a Norton double-grit waterstone and a very solid
adjustable rubber clamp base so the stone doesn\'t slide around and/or
damage the countertops.

.<https://www.amazon.com/dp/B0006NFDOY?psc=1&ref=ppx_pop_dt_b_product_details

.<https://www.amazon.com/dp/B00NFB2MTI?psc=1&ref=ppx_pop_dt_b_product_details

I just gave this set to a family member whose knives were essentially
useless. I did the initial sharpening on two of them, and people were
astonished at the difference, even though those blades were made of
very soft steel. (Unlike Wusthof).

She will also be getting a polyethylene cutting board - she used to
cut on ceramic plates, ruining both plate and knife.


I got Mo a 48\" Sony oled TV. It\'s astonishing. It makes the old LCD
look washed-out and fuzzy.

I got a 48\" Sony for my wife a few years ago, with full HD (had to
upgrade COMCAST service as well). The improvement was stunning,
especially for baseball and football (US) games. She also likes to
watch French movies on Netflix, to improve her French.

Joe Gwinn

I\'m looking forward to more OLEDs in instruments. They are bright,
sharp, color saturated, and have great viewing angles.

Beware burn-in (also called printing). I avoided OLEDs for just this
reason. This will eventually be fixed, but very gradually.

On your instruments, it may be necessary to have the fixed part of the
display wander around a bit, like we did for CRTs, to smear out and
thus reduce the visual impact of printing.

Comcast gets maligned a lot, but they have been great for us. They
keep upgrading speed and video quality to be competitive. I\'m now
getting 130+40 mbps on the basic plan, which is about as fast as
anyone needs.

That\'s been the pattern in the Boston area as well. Of course, they
have Verizon with Fios snapping at their heels. And vice versa.

The pattern is that bandwidth is essentially free to the providers, so
if you complain about anything they upgrade your speed to appease you.
Both Comcast and Suddenlink did that for us when we had a complaint.

I haven\'t tested that gambit here.

What\'s going on in New England with Verizon is that they are going to
drop all analog land-line telephone service (over copper), but when
asked about how long things work when the power is out, or what the
achieved operational availability is, they disappear into a cloud of
sales happy-talk.

For the record, the traditional holdup time is 48 hours on the
central-office battery (time for the diesel generators to arrive), and
five nines (0.99999).

Joe Gwinn

Cell phones don\'t last a day, and struggle to achieve one nine.

 

[server]

On Sun, 26 Dec 2021 13:17:16 -0500, Joe Gwinn <joegwinn@comcast.net>
wrote:

On Sun, 26 Dec 2021 09:55:34 -0800, jlarkin@highlandsniptechnology.com
wrote:

On Sun, 26 Dec 2021 12:37:54 -0500, Joe Gwinn <joegwinn@comcast.net
wrote:

On Sat, 25 Dec 2021 21:33:00 -0800, jlarkin@highlandsniptechnology.com
wrote:

[snip]

I got a beautiful set of razor sharp Wusthof knives. They slice
through Tartine sourdough like a chain saw. Pay no mind to the
band-aids.

Yeah. They will dull gradually, and need whetting from time to time.
What I use is a Norton double-grit waterstone and a very solid
adjustable rubber clamp base so the stone doesn\'t slide around and/or
damage the countertops.

.<https://www.amazon.com/dp/B0006NFDOY?psc=1&ref=ppx_pop_dt_b_product_details

.<https://www.amazon.com/dp/B00NFB2MTI?psc=1&ref=ppx_pop_dt_b_product_details

I just gave this set to a family member whose knives were essentially
useless. I did the initial sharpening on two of them, and people were
astonished at the difference, even though those blades were made of
very soft steel. (Unlike Wusthof).

She will also be getting a polyethylene cutting board - she used to
cut on ceramic plates, ruining both plate and knife.


I got Mo a 48\" Sony oled TV. It\'s astonishing. It makes the old LCD
look washed-out and fuzzy.

I got a 48\" Sony for my wife a few years ago, with full HD (had to
upgrade COMCAST service as well). The improvement was stunning,
especially for baseball and football (US) games. She also likes to
watch French movies on Netflix, to improve her French.

Joe Gwinn

I\'m looking forward to more OLEDs in instruments. They are bright,
sharp, color saturated, and have great viewing angles.

Beware burn-in (also called printing). I avoided OLEDs for just this
reason. This will eventually be fixed, but very gradually.

On your instruments, it may be necessary to have the fixed part of the
display wander around a bit, like we did for CRTs, to smear out and
thus reduce the visual impact of printing.

People tell me that they have had OLED TVs for years without problems.
But TVs are pretty sophisticated and have varying images. Instruments
with dumb OLEDs and fixed-position numeric displays might wear out the
pixels.

If Mo\'s TV only looks fabulous for two or three years, I\'ll get her
another one.

Slowly moving the image on an OLED instrument is a good idea. The
viewing angle issues on LCDs can be a problem and restricts color
choices. Both benchtop and rackmount instruments can be used at large
vertical viewing angles, which TVs don\'t have.







--

I yam what I yam - Popeye

 

[Jan Panteltje]

On a sunny day (Sun, 26 Dec 2021 13:17:16 -0500) it happened Joe Gwinn
<joegwinn@comcast.net> wrote in <fnbhsg1ok5tr08guoj0vqjeorkha895266@4ax.com>:

On Sun, 26 Dec 2021 09:55:34 -0800, jlarkin@highlandsniptechnology.com
wrote:

On Sun, 26 Dec 2021 12:37:54 -0500, Joe Gwinn <joegwinn@comcast.net
wrote:

On Sat, 25 Dec 2021 21:33:00 -0800, jlarkin@highlandsniptechnology.com
wrote:

[snip]

I got a beautiful set of razor sharp Wusthof knives. They slice
through Tartine sourdough like a chain saw. Pay no mind to the
band-aids.

Yeah. They will dull gradually, and need whetting from time to time.
What I use is a Norton double-grit waterstone and a very solid
adjustable rubber clamp base so the stone doesn\'t slide around and/or
damage the countertops.

.<https://www.amazon.com/dp/B0006NFDOY?psc=1&ref=ppx_pop_dt_b_product_details

.<https://www.amazon.com/dp/B00NFB2MTI?psc=1&ref=ppx_pop_dt_b_product_details

I just gave this set to a family member whose knives were essentially
useless. I did the initial sharpening on two of them, and people were
astonished at the difference, even though those blades were made of
very soft steel. (Unlike Wusthof).

She will also be getting a polyethylene cutting board - she used to
cut on ceramic plates, ruining both plate and knife.


I got Mo a 48\" Sony oled TV. It\'s astonishing. It makes the old LCD
look washed-out and fuzzy.

I got a 48\" Sony for my wife a few years ago, with full HD (had to
upgrade COMCAST service as well). The improvement was stunning,
especially for baseball and football (US) games. She also likes to
watch French movies on Netflix, to improve her French.

Joe Gwinn

I\'m looking forward to more OLEDs in instruments. They are bright,
sharp, color saturated, and have great viewing angles.

Beware burn-in (also called printing). I avoided OLEDs for just this
reason. This will eventually be fixed, but very gradually.

I second that, I replaced the OLED in my clock last month,
became unreadable, segments of numbers burned in.
After 7 years that is, for a TV you would want it replaced much much earlier.
But I already told him that month ago.
My Samsung LCD TV keeps amazing me after how many ? 9 years or so.

On your instruments, it may be necessary to have the fixed part of the
display wander around a bit, like we did for CRTs, to smear out and
thus reduce the visual impact of printing.

Yes
Using a lot of those small OLED
http://panteltje.com/pub//OLED_character_generator_working_IMG_4254.JPG

Cheap, about 2$50 like this:
https://www.ebay.com/itm/173310429823
I have some blue + yellow and some white ones, all i2c interface.

 

[Phil Hobbs]

jlarkin@highlandsniptechnology.com wrote:

On Sat, 25 Dec 2021 17:57:39 -0500, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

jlarkin@highlandsniptechnology.com wrote:
On Fri, 24 Dec 2021 20:47:01 -0800 (PST), whit3rd <whit3rd@gmail.com
wrote:

On Friday, December 24, 2021 at 2:21:29 PM UTC-8, John Larkin wrote:
I have a differential output from a fast CML flipflop, powered by +3
and ground, and want to drive another CML-input part. If the load
gadget was also powered from +3, I\'d just connect them with a couple
of 50 ohm traces. But the Vcc of the destination part could be
anything from +3 to -2.

I want full speed and DC coupling, so the ideal part to put in series
with both runs is a battery of the appropriate voltage,

So, do that. Just a capacitor, obviously, won\'t have the constant DC step
if there\'s any low frequencies present, but you can put a three-transistor
current mirror dual-source on the most positive rail, and another three-transistor
current mirror dual-sink on the most negative rail, and connect the input
transistors\' bases of those mirrors with the appropriate resistor to make
a constant-current bias. Then, instead of coupling capacitor alone, you
put a bit of bypass resistor across each capacitor, and feed the high terminal
with one source, and the low terminal with one sink (and \'cuz it\'s differential, you\'d
have the second source and sink for the other half\'s capacitor).

As long as you don\'t dial the current up beyond what the CML sources , it\'ll drive
a lot like a battery in series. If the HF gets too much Miller effect, a few ferrite beads
can help, obviously.

You do have to know polarity of the offset required at wiring-time,
but the mirrors\' emitter supplies are places you can apply
dynamic controls of the amplitude and range of offset.

The polarity can go either way, which sure doesn\'t help.

In this case, I want to couple logic levels with features from maybe
50 ps to 50 years. I might grudgingly allow the two traces between
chips to be half an inch long, with one sideways cap in the middle of
each. That\'s no place for a dozen transistors or ICs. My circuit
started as two floating programmable voltages across the coupling
caps, and stepwise deteriorated to the simple thing I have now. The
big resistors fake dueling current sources, and the dropping resistor
across the cap turns out to work at infinite ohms.

There is a more general issue of splitting a signal into a number of
bandwidths, transmitting, and then recombining neatly. Phil Hobbs
recently needed to drive a ganfet gate with a fast-edge fairly long
pulse, when the fet is riding hundreds of volts off ground. I don\'t
know how he wound up doing that.

Hasn\'t been implemented yet. Probably something like this:
https://electrooptical.net/www/sed/IsolatedGaN.zip>.

The Coilcraft transformer is way too clunky, so it\'ll either be an RC or
a much lighter-weight transformer--maybe one of your
coax-jumper-plus-potcore things. (The switch has to ride on top of a
-450V avalanche photodiode bias supply.)

You could maybe use a memory element on the high side, a flipflop or a
schmitt trigger or maybe even just a capacitor, and drive it from
narrow positive and negative spikes through a transformer. That could
be done with zero static power required on the high side.

The non-inverting schmitt case has analogies to my pulse coupler. Cap
to the schmitt input, feedback resistor to sustain. Might work.

There\'s a requirement for 10 ns recovery from overload, which would need
a reasonably-beefy driver even with GaN. In reality it\'s a nice-to-have
and not a deal breaker, but it presented a very interesting design
challenge--how do you make a capacitively-coupled APD bootstrap recover
that fast, and avoid dumping the fault current straight into the
bootstrap cap when the switch opens?

The APD gain is a strong function of bias, so you can\'t ignore that part
of the problem--otherwise it\'ll take tens of milliseconds to recover.

And of course it all has to float at -400 to -500 volts, with minimal
capacitance to ground because the local ground is being driven by the
bootstrap transistor.

Fun.

Cheers

Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[Rich S]

On Sunday, December 26, 2021 at 6:54:26 PM UTC, jla...@highlandsniptechnology.com wrote:

On Sun, 26 Dec 2021 13:17:16 -0500, Joe Gwinn <joeg...@comcast.net
wrote:

On Sun, 26 Dec 2021 09:55:34 -0800, jla...@highlandsniptechnology.com
wrote:

On Sun, 26 Dec 2021 12:37:54 -0500, Joe Gwinn <joeg...@comcast.net
wrote:

On Sat, 25 Dec 2021 21:33:00 -0800, jla...@highlandsniptechnology.com
wrote:

[snip]

I got a beautiful set of razor sharp Wusthof knives. They slice
through Tartine sourdough like a chain saw. Pay no mind to the
band-aids.

Yeah. They will dull gradually, and need whetting from time to time.
What I use is a Norton double-grit waterstone and a very solid
adjustable rubber clamp base so the stone doesn\'t slide around and/or
damage the countertops.

.<https://www.amazon.com/dp/B0006NFDOY?psc=1&ref=ppx_pop_dt_b_product_details

.<https://www.amazon.com/dp/B00NFB2MTI?psc=1&ref=ppx_pop_dt_b_product_details

I just gave this set to a family member whose knives were essentially
useless. I did the initial sharpening on two of them, and people were
astonished at the difference, even though those blades were made of
very soft steel. (Unlike Wusthof).

She will also be getting a polyethylene cutting board - she used to
cut on ceramic plates, ruining both plate and knife.


I got Mo a 48\" Sony oled TV. It\'s astonishing. It makes the old LCD
look washed-out and fuzzy.

I got a 48\" Sony for my wife a few years ago, with full HD (had to
upgrade COMCAST service as well). The improvement was stunning,
especially for baseball and football (US) games. She also likes to
watch French movies on Netflix, to improve her French.

Joe Gwinn

I\'m looking forward to more OLEDs in instruments. They are bright,
sharp, color saturated, and have great viewing angles.

Beware burn-in (also called printing). I avoided OLEDs for just this
reason. This will eventually be fixed, but very gradually.

On your instruments, it may be necessary to have the fixed part of the
display wander around a bit, like we did for CRTs, to smear out and
thus reduce the visual impact of printing.
People tell me that they have had OLED TVs for years without problems.
But TVs are pretty sophisticated and have varying images. Instruments
with dumb OLEDs and fixed-position numeric displays might wear out the
pixels.

If Mo\'s TV only looks fabulous for two or three years, I\'ll get her
another one.

Slowly moving the image on an OLED instrument is a good idea. The
viewing angle issues on LCDs can be a problem and restricts color
choices. Both benchtop and rackmount instruments can be used at large
vertical viewing angles, which TVs don\'t have.
--

I yam what I yam - Popeye

congrats, John, a find choice. We\'ve not experienced
screen burn-in on the OLEDs (tho we only test them
for about a week). Still, sensible to be cautious.
If it gives you some comfort,
Sony TVs have had very high predicted reliability
and owner satisfaction scores, for many
years in a row, per the CR survey results. And their
OLEDs have performed excellently.
(Of course, we aim for high-fidelity reproduction,
turn off the image-boosting gimmicks, use the
\"custom\" picture setting mode, and calibrate the
image using CalMan setup. Luckily
the model you bought has CalMan Software
already built in! (XBR-48A9S) - though
I dont know how they expect you to
find the optical sensor.)
Curious to know how you like the sound of
the \"Acoustic surface audio\" feature
(which uses the screen itself as the acoustic
radiators, not conventional dynamic drivers.)

 

[server]

On Fri, 24 Dec 2021 14:21:18 -0800, John Larkin
<jlarkin@highland_atwork_technology.com> wrote:

I have a differential output from a fast CML flipflop, powered by +3
and ground, and want to drive another CML-input part. If the load
gadget was also powered from +3, I\'d just connect them with a couple
of 50 ohm traces. But the Vcc of the destination part could be
anything from +3 to -2.

I want full speed and DC coupling, so the ideal part to put in series
with both runs is a battery of the appropriate voltage, namely the
difference in supply voltages. Couldn\'t find anything that would work
like that.

Here is a \"feed-beside\" version. It works but does some tricky,
barely-legal things to the CML source gate. CML gates can maybe
usually swing 800 mV down from their Vcc rail and maybe a bit above.


Version 4
SHEET 1 1428 972
WIRE 448 -176 320 -176
WIRE 320 -144 320 -176
WIRE 160 -128 32 -128
WIRE 272 -128 160 -128
WIRE 448 -112 448 -176
WIRE 32 -96 32 -128
WIRE 160 -96 160 -128
WIRE 272 -80 224 -80
WIRE 320 -32 320 -64
WIRE 160 0 160 -32
WIRE 224 0 224 -80
WIRE -48 80 -112 80
WIRE 32 80 32 -16
WIRE 32 80 -48 80
WIRE 192 80 32 80
WIRE 448 80 448 -32
WIRE 448 80 256 80
WIRE 512 80 448 80
WIRE 624 80 512 80
WIRE 32 112 32 80
WIRE -112 128 -112 80
WIRE 448 144 448 80
WIRE 816 224 752 224
WIRE 864 224 816 224
WIRE -112 256 -112 208
WIRE 32 256 32 192
WIRE 448 256 448 224
WIRE 752 304 752 224
WIRE 624 320 624 80
WIRE 704 320 624 320
WIRE 704 368 624 368
WIRE 448 416 320 416
WIRE 752 432 752 384
WIRE 320 448 320 416
WIRE 160 464 32 464
WIRE 272 464 160 464
WIRE 448 480 448 416
WIRE 32 496 32 464
WIRE 160 496 160 464
WIRE 272 512 224 512
WIRE 320 560 320 528
WIRE 160 592 160 560
WIRE 224 592 224 512
WIRE -48 672 -112 672
WIRE 32 672 32 576
WIRE 32 672 -48 672
WIRE 192 672 32 672
WIRE 448 672 448 560
WIRE 448 672 256 672
WIRE 512 672 448 672
WIRE 624 672 624 368
WIRE 624 672 512 672
WIRE 32 704 32 672
WIRE -112 720 -112 672
WIRE 448 736 448 672
WIRE -112 848 -112 800
WIRE 32 848 32 784
WIRE 448 848 448 816
FLAG 32 256 0
FLAG 448 256 0
FLAG 320 -32 0
FLAG 160 0 0
FLAG 224 0 0
FLAG 512 80 Q+
FLAG -112 256 0
FLAG -48 80 CML+
FLAG 32 848 0
FLAG 448 848 0
FLAG 320 560 0
FLAG 160 592 0
FLAG 224 592 0
FLAG 512 672 Q-
FLAG -112 848 0
FLAG -48 672 CML-
FLAG 752 432 0
FLAG 816 224 DIFF
SYMBOL res 48 208 R180
WINDOW 0 49 55 Left 2
WINDOW 3 51 25 Left 2
SYMATTR InstName R1
SYMATTR Value 50
SYMBOL cap 256 64 R90
WINDOW 0 71 30 VBottom 2
WINDOW 3 73 34 VTop 2
SYMATTR InstName C1
SYMATTR Value 1µ
SYMBOL res 464 240 R180
WINDOW 0 64 62 Left 2
WINDOW 3 67 28 Left 2
SYMATTR InstName R2
SYMATTR Value 50
SYMBOL e 320 -160 R0
WINDOW 0 44 81 Left 2
WINDOW 3 44 112 Left 2
SYMATTR InstName E1
SYMATTR Value 20
SYMBOL res 432 -128 R0
WINDOW 0 48 50 Left 2
WINDOW 3 50 78 Left 2
SYMATTR InstName R3
SYMATTR Value 2K
SYMBOL res 48 0 R180
WINDOW 0 59 76 Left 2
WINDOW 3 54 42 Left 2
SYMATTR InstName R4
SYMATTR Value 25k
SYMBOL cap 144 -96 R0
WINDOW 0 -49 21 Left 2
WINDOW 3 -49 55 Left 2
SYMATTR InstName C2
SYMATTR Value 1n
SYMBOL current -112 128 R0
WINDOW 0 -64 101 Left 2
WINDOW 3 -56 172 Left 2
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName Icml
SYMATTR Value PULSE(16m 0 10u 0 0 50u 100u 10)
SYMBOL bi -112 720 R0
WINDOW 0 -86 52 Left 2
WINDOW 3 -164 90 Left 2
SYMATTR InstName B1
SYMATTR Value I=16m-I(Icml)
SYMBOL res 48 800 R180
WINDOW 0 49 55 Left 2
WINDOW 3 51 25 Left 2
SYMATTR InstName R5
SYMATTR Value 50
SYMBOL cap 256 656 R90
WINDOW 0 71 30 VBottom 2
WINDOW 3 73 34 VTop 2
SYMATTR InstName C3
SYMATTR Value 1µ
SYMBOL res 464 832 R180
WINDOW 0 62 85 Left 2
WINDOW 3 62 52 Left 2
SYMATTR InstName R6
SYMATTR Value 50
SYMBOL e 320 432 R0
WINDOW 0 44 81 Left 2
WINDOW 3 44 112 Left 2
SYMATTR InstName E2
SYMATTR Value 20
SYMBOL res 432 464 R0
WINDOW 0 48 50 Left 2
WINDOW 3 49 82 Left 2
SYMATTR InstName R7
SYMATTR Value 2K
SYMBOL res 48 592 R180
WINDOW 0 59 76 Left 2
WINDOW 3 54 42 Left 2
SYMATTR InstName R8
SYMATTR Value 25k
SYMBOL cap 144 496 R0
WINDOW 0 -49 21 Left 2
WINDOW 3 -49 55 Left 2
SYMATTR InstName C4
SYMATTR Value 1n
SYMBOL e 752 288 R0
WINDOW 0 58 35 Left 2
WINDOW 3 65 70 Left 2
SYMATTR InstName E3
SYMATTR Value 1
TEXT 688 816 Left 2 !.tran 2m
TEXT 536 736 Left 2 ;CML-CML Feed-Beside Level Shifter B1\\n J Larkin
Dec 27 2021
TEXT -64 232 Left 2 ;gnd1
TEXT 360 264 Left 2 ;gnd2
TEXT -64 824 Left 2 ;gnd1
TEXT 352 856 Left 2 ;gnd2




--

I yam what I yam - Popeye

 

[Jan Panteltje]

On a sunny day (Mon, 27 Dec 2021 05:17:01 -0800) it happened
jlarkin@highlandsniptechnology.com wrote in
<6vejsg10736f1vrhjbqit2s8b3sc53vdni@4ax.com>:

The sound is fabulous on the Sony OLED tv. At first powerup it
calibrated itself to the room acoustics!

It has overcome a major point of marital discord. I like the sound to
be loud and Mo likes it low. This tv somehow makes us both happy.

Sony did acquire a bad name here in TV starting when the PAL system was introduced
they did not want to pay for the PAL patents so basically used a NTSC type decoder, losing
the advantage that PAL has no color errors.
The second thing was the \'trinitron\' tube that was brighter than the normal shadow mask tubes in color TVs,
but had some drawbacks for example in case of vibration making support wires visible.
https://en.wikipedia.org/wiki/Trinitron#Visible_support_or_damping_wires
sold a lot with the very bright hype,

That was all many years ago so maybe they changed ways.
The sound of my Samsung TV is bad (acoustics), so I use external speakers or headphones, earphones.

Oh and Sony had the KV1810 TV chassis that used silicon switches_ not transistors, in the power supply and deflection too IIRC.
The sets manufactured in the UK had bad solder joints that would interrupt the switch-off and kill its supply.

They make good stuff too, had a Sony tape recorder and their camera sensors are OK too.

It is a good idea to look up a lot of reviews before buying stuff.

 

[server]

On Sun, 26 Dec 2021 23:58:36 -0800 (PST), Rich S
<richsulinengineer@gmail.com> wrote:

On Sunday, December 26, 2021 at 6:54:26 PM UTC, jla...@highlandsniptechnology.com wrote:
On Sun, 26 Dec 2021 13:17:16 -0500, Joe Gwinn <joeg...@comcast.net
wrote:

On Sun, 26 Dec 2021 09:55:34 -0800, jla...@highlandsniptechnology.com
wrote:

On Sun, 26 Dec 2021 12:37:54 -0500, Joe Gwinn <joeg...@comcast.net
wrote:

On Sat, 25 Dec 2021 21:33:00 -0800, jla...@highlandsniptechnology.com
wrote:

[snip]

I got a beautiful set of razor sharp Wusthof knives. They slice
through Tartine sourdough like a chain saw. Pay no mind to the
band-aids.

Yeah. They will dull gradually, and need whetting from time to time.
What I use is a Norton double-grit waterstone and a very solid
adjustable rubber clamp base so the stone doesn\'t slide around and/or
damage the countertops.

.<https://www.amazon.com/dp/B0006NFDOY?psc=1&ref=ppx_pop_dt_b_product_details

.<https://www.amazon.com/dp/B00NFB2MTI?psc=1&ref=ppx_pop_dt_b_product_details

I just gave this set to a family member whose knives were essentially
useless. I did the initial sharpening on two of them, and people were
astonished at the difference, even though those blades were made of
very soft steel. (Unlike Wusthof).

She will also be getting a polyethylene cutting board - she used to
cut on ceramic plates, ruining both plate and knife.


I got Mo a 48\" Sony oled TV. It\'s astonishing. It makes the old LCD
look washed-out and fuzzy.

I got a 48\" Sony for my wife a few years ago, with full HD (had to
upgrade COMCAST service as well). The improvement was stunning,
especially for baseball and football (US) games. She also likes to
watch French movies on Netflix, to improve her French.

Joe Gwinn

I\'m looking forward to more OLEDs in instruments. They are bright,
sharp, color saturated, and have great viewing angles.

Beware burn-in (also called printing). I avoided OLEDs for just this
reason. This will eventually be fixed, but very gradually.

On your instruments, it may be necessary to have the fixed part of the
display wander around a bit, like we did for CRTs, to smear out and
thus reduce the visual impact of printing.
People tell me that they have had OLED TVs for years without problems.
But TVs are pretty sophisticated and have varying images. Instruments
with dumb OLEDs and fixed-position numeric displays might wear out the
pixels.

If Mo\'s TV only looks fabulous for two or three years, I\'ll get her
another one.

Slowly moving the image on an OLED instrument is a good idea. The
viewing angle issues on LCDs can be a problem and restricts color
choices. Both benchtop and rackmount instruments can be used at large
vertical viewing angles, which TVs don\'t have.
--

I yam what I yam - Popeye

congrats, John, a find choice. We\'ve not experienced
screen burn-in on the OLEDs (tho we only test them
for about a week). Still, sensible to be cautious.
If it gives you some comfort,
Sony TVs have had very high predicted reliability
and owner satisfaction scores, for many
years in a row, per the CR survey results. And their
OLEDs have performed excellently.
(Of course, we aim for high-fidelity reproduction,
turn off the image-boosting gimmicks, use the
\"custom\" picture setting mode, and calibrate the
image using CalMan setup. Luckily
the model you bought has CalMan Software
already built in! (XBR-48A9S) - though
I dont know how they expect you to
find the optical sensor.)
Curious to know how you like the sound of
the \"Acoustic surface audio\" feature
(which uses the screen itself as the acoustic
radiators, not conventional dynamic drivers.)

You\'re right, the sound comes out of the flat screen. Upper corners
are treble. It\'s amazing. Sounds great.



--

I yam what I yam - Popeye