Chip with simple program for Toy

[Chris]

PeteS wrote:

jacko wrote:
nnn wrote:
Hi,
I have seen a scope which has

1 Mohm 30 pF input impedance

and frequency response

0 to 12MHz (+/- 3dB)

My question:

What is the difference between input impedance
and frequency response?

input impedance has to be driven, and so will prsent power transfer to
the voltage mesurement equipment, and the 3db response of the line by
wobble matching the graticule scale, will be the bandwidth. the line
driver has its own input impedance, which can only be driven by limited
power.

ok?


Huh? (in response to what Jacko wrote)

x-posted to s.e.b where this is more appropriate.

The input impedance of the measurement device specifies the load it
presents to the signal being measured. It is important to know for a
number of reasons.

The +/-3dB response is specified as that is how bandwidth is normally
specified (-3dB is a half power point). In this case, it specifies that
the amplitude response of the scope is within 3dB between DC and 12MHz.

I would suggest a google search for some basics (although s.e.b. can be
an appropriate forum too).

Cheers

PeteS

And the OP can also look at the ultimate scope reference for newbies,
"The XYZs of Oscilloscopes" from the folks at Tektronics. He'll have
to fill out a quick questionaire before downloading:

http://www.tek.com/Measurement/programs/301913X312631/

Cheers
Chris

 

[Don McKenzie]

Rich Grise wrote:

Crossposted to sci.electronics.design,sci.electronics.basics,
followups-to: sci.electronics.basics

On Thu, 02 Nov 2006 14:22:56 +0100, Enzo Ternavasio wrote:


I have used many alphanumeric displays, with 1,2, 4 lines.
If I use a graphical display, will it be more difficult to use it as an
alphanumeric display?
I mean, writing only numbers and labels ?

here is an alternative that will take the hard work out of this.
http://www.dontronics-shop.com/home.php?cat=263

Don...


--
Don McKenzie
E-Mail Contact Page: http://www.dontronics.com/e-mail.html

Micro,TTL,USB to 1.5" color LCD http://www.dontronics.com/micro-lcd.html
USB,RS232 or TTL to VGA Monitor http://www.dontronics.com/micro-vga.html
World's smallest USB 2 TTL Conv http://www.dontronics.com/micro-usb.html

 

[joseph2k]

billcalley wrote:

Hi All,

I have a balanced 50 ohm 915MHz filter on a PCB that I need to test.
Would it work OK if I simply shunted one leg of the balanced
filter's input and output with a 50 ohm resistor to ground, while
sweeping the other balanced input and output with a VNA? Is this the
easiest way to test a balanced circuit for gain and return loss with a
typical VNA? (I have no room at all to place 1:1 baluns on my PCB for
the (unbalanced) 50 ohm VNA).

Thanks!

-Bill

Unless your parameters are truly difficult, just plug it in to your
unbalanced (normal) VNA. Works pretty well up to 6GHz, of course
terminations are paramount.

--
JosephKK
Gegen dummheit kampfen die Gotter Selbst, vergebens.  
--Schiller

 

[Chris]

Rich Grise wrote:

On Wed, 22 Nov 2006 18:24:32 -0500, Steven Skindell wrote:

I have a 5v 10ma line when hot would like to turn on a relay to turn on a
9.6v motor.
ould somebody please tell me how I would accomplish this using a transistor?


I've transposted this to news:sci.electronics.basics, which is where it
belongs.

Cheers!
Rich

Hi, Steven. Could you give more information? Like how much current
does your motor draw, do you have a 5V supply available? Do you have a
9.6V supply, or another voltage? Will your motor run properly on 8.6V
(say, if 1V was dropped across a darlington transistor)?

A standard bipolar transistor can be used as a switch, but to do it
properly, you need a little more to work with.

Good luck
Chris

 

[PeteS]

Joe G (Home) wrote:

I never asked for any technical support to design the RFID Tag- as I read my
posts correctly again (I was after more of the proceedures for project
management to educate myself and my boss).

Some posted a question and asked what I was intending to design... so in
repsonse... I provided a little information.

I have 2 methods for waking up the RFID with a typical continous drain
current ~ 6uA.

Sorry to have offended you.

No problem; Genome seems to offend himself (must have something to do
with the soap)

Cheers

PeteS

"Genome" <mrspamizgood@yahoo.co.uk> wrote in message
news:dp6dh.83$Y4.38@newsfe6-win.ntli.net...

"Joe G (Home)" <joe.g@optusnet.com.au> wrote in message
news:4573e404$0$5749$afc38c87@news.optusnet.com.au...
Thanks guys.

The product is an active RFID tag... >> -----
END


BASTARD.

It's an interesting comment on the state of the human race that creates a
market for RFID tags.....

It gets worse when people don't know how to do them need to disguise an
'original' question before they drop their bomb......

Hi All.
Hi Group.
Hi Guys.
La la la la la.

I'm looking for a pink thing and I haven't decided what shade of pink I'd
like it to be so I thought I'd come along and ask your opinions about
shades of pink......

Looking forward to your input, team.

....................................................

Thanks Guys, all of your input was really appreciated. By the way this is
an RFID tag and I was also wondering about some other stuff..... Like, how
does RFID work?

Dribble
Dribble
Dribble

FUCK OFF!

DNA

 

Michael A. Terrell wrote:

maxfoo@punkass.com wrote:

karthik wrote:
How to calculate the required rechargeable battery specifcation(
Lithium ).I want to use in UPS for my Colour televison & Music systems
for period of about 2 hrs.Hope anyone will help.

It be cheaper to buy a honda generator and running it for 2 hours on a
gallon of fuel.


Not when I have 14 spare UPS I got for free.

What?, It was directed to the OP not you...

 

[Eeyore]

"ehoosee.tianya.cn" wrote:

A capacity.
the power comsumption is only 50uA in POWER DOWN mode.

How much capacitance ?

What's going to supply the power in power down mode ?

Graham

 

[Michael A. Terrell]

niftydog wrote:

Michael A. Terrell wrote:
Another way is to use op amps
with a split supply so that there is no DC offset to require caps.
Switching can even be mechanical, if the inputs and outputs are properly
buffered. This is common in commercial audio gear for broadcast work.

DC offset is always present within the effects themselves because 99.9%
of them all run on single supplies. You've still got to deal with that
at some point in the circuit.

Buffering every in and out adds to the complexity again, most don't want
to put that much time, effort and money into a project like this.
Especially given that many who embark on such a project are electronics
amateurs. You start with a few simple DPDT foot switches and end up with
a microprocessor controlled, DSP driven, GPS equipped nightmare!

niftydog

That is where the buffers come in. Four op amps in a single
packageand dierectly couipled to the input or output caps. Since there
is no switching the single suppy circuits, the problem goes away. Even
better would be to modify the effects unit to a split supply


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[Grostle News]

Homer J wrote:

Ever seen it coming out of the boss's new
$250,000 molding machine?

No, but it is that type of thing that makes electronics a hobby for me,
and not a career.

saxum g.n.

 

[Michael A. Terrell]

Grostle News wrote:

Homer J wrote:

Ever seen it coming out of the boss's new
$250,000 molding machine?

No, but it is that type of thing that makes electronics a hobby for me,
and not a career.

saxum g.n.

That's what happens whenever Homer messes with something. No wonder
his favorite beer is called Duff.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[Homer J Simpson]

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:45B7AC4A.E4A65D63@earthlink.net...

Ever seen it coming out of the boss's new
$250,000 molding machine?

No, but it is that type of thing that makes electronics a hobby for me,
and not a career.

That's what happens whenever Homer messes with something. No wonder
his favorite beer is called Duff.

Nope. That's what happens when you let the Yanks build one instead of the
Swiss.




--
..
..
..
..
..
..
..
..

 

[jasen]

On 2007-01-27, Shaine <shanugulati@gmail.com> wrote:

Ogleo word has been derived from word Ogle \O"gle\, n, which means
to look at.

And the fact that it's an anagram of google is purely coincidental,,,,

yeah, right,


Bye.
Jasen

 

[David L. Jones]

On Jan 29, 3:30 pm, "panfilero" <panfil...@gmail.com> wrote:

Hello

I need to deliver a variable current between 0-2 Amps to a small load
(15 Ohms).... At first I was thinking about building a current
amplifier..... but after investigating that route again, i think, it's
too difficult to build.

Then I heard about adjustable voltage regulators. And looking through
the datasheet of an LM117, I noticed it had a curcuit example it
called: "Precision Current Limiter" where the output current is
controlled by a potentiometer and can be varied from 0 to 1.65 Amps.

I'm not sure if this is a variable constant current source, but it
kinda sounds like it to me, is anyone familiar with this circuit?

Yep, it is a standard (adjustable) constant current building block
circuit used in a zillion applications.

Dave

 

[panfilero]

"all" you need to do is scale the 0-5V up to 0 - 30V the 15 ohm resistance
will convert the voltage to 0-2 A

My load changes non-linearly with the voltage across it, that's when
i'm trying to steer towards a steady current. My load is a Shape
Memory Alloy wire.

thanks

 

[Jon Slaughter]

"panfilero" <panfilero@gmail.com> wrote in message
news:1170079659.906597.260680@q2g2000cwa.googlegroups.com...

"all" you need to do is scale the 0-5V up to 0 - 30V the 15 ohm
resistance
will convert the voltage to 0-2 A


My load changes non-linearly with the voltage across it, that's when
i'm trying to steer towards a steady current. My load is a Shape
Memory Alloy wire.

Then use a meter to measure the current. Surely the load doesn't change with
a fixed voltage applied to it? Essentially you will be building a constant
current source anyways(ultimately its a voltage regulator anyways and you
can find schematics to build constant current sources in many of the voltage
regulators datasheets).

That is, even if your load is non linear as long as your load does vary with
time then it should be good enough.

i.e., by Ohms law V = F(I). As long as F isn't to complicated you can solve
for I in terms of V. If we assume F is injective on some bounded interval
then we can find the inverse of F.

So how to do this easily in practice? If you know the bounds on your load
then you can plug in a voltage and measure the current and then adjust V
until you get the current you want. Essentially you yourself is the constant
current source.

Say your load registers 1A at 10V but you want to supply 1.5A's. What to do?
Try increasing V to 11V and see how much your current changes and which
direction(although its most likely in the same direction as the change in
current).

Doing this you can put any current you want through the load and as long as
the load doesn't depend on t to much then it will be pretty accurate.

Essentially you can map out the V-I curve doing this and get the dynamic
resistance of your load. I don't know about memory alloys but as long as
they don't get to hot then it will work fine. It really depends on your
application though. You'll just get a different V-I graph for different
temperatures.

If you plan on doing a lot of work with it you will be better suited to get
a constant current source though. It would be much easier to turn then dial
to the current you need instead of measuring the current and voltage.
(although it wouldn't be so bad with two multimeters, one measuring current
and the other voltage.)

Ofcourse there are some issues with my method above as there is no current
regulation. If the load changes with time it could cause some serious
problems. A constant current source is just a voltage source that will
change the voltage to that it can deliver a constant current. Essentially my
quick and dirty method above is where you become the control feedback
circuit. Not the best way but works in a pinch.

Jon

 

[Paul E. Schoen]

"panfilero" <panfilero@gmail.com> wrote in message
news:1170045009.073294.142060@v45g2000cwv.googlegroups.com...

Hello

I need to deliver a variable current between 0-2 Amps to a small load
(15 Ohms).... At first I was thinking about building a current
amplifier..... but after investigating that route again, i think, it's
too difficult to build.

Then I heard about adjustable voltage regulators. And looking through
the datasheet of an LM117, I noticed it had a curcuit example it
called: "Precision Current Limiter" where the output current is
controlled by a potentiometer and can be varied from 0 to 1.65 Amps.

I'm not sure if this is a variable constant current source, but it
kinda sounds like it to me, is anyone familiar with this circuit?

In the "Precision Current Limiter" circuit the current is controlled
by a potentiometer, but I need to control the current with a variable
voltage (between 0 - 5 V), is there such a thing as a voltage
controlled resistor? So that I could use that in this circuit?

any help is greatly appreciated,
thank you
Joshua

[limited crossposting to two]

I made two circuits that may do what you want, using just two transistors
and some resistors and diodes. The first one uses bipolar transistors, and
the second uses MOSFETs, which seem to be more linear. You may want to use
devices that are better rated for the purpose than what I found in the
LTspice library. In each case, the voltage input varies from Vbe or VgsOn
to about 2 volts above that, to vary the output from zero to two amperes. I
tried it with loads from 1 ohm to 15 ohms and it stays close to 2 amperes
(or wherever you set the current). You need a raw supply of 35 to 40 volts
to get the 30 volts into 15 ohms. I used a one ohm sense resistor, which
drops 2 volts at full current, but you might get by with 0.5 ohms or less.
Temperature stability will be an issue with this circuit, but it might do
the job. Of course, an op-amp could be used with current feedback to
achieve near perfect regulation. The LTspice files follow:

Paul

========================= CurrAmp.asc =================================

Version 4
SHEET 1 880 680
WIRE -144 -64 -256 -64
WIRE -80 -64 -144 -64
WIRE 32 -64 0 -64
WIRE 432 -64 128 -64
WIRE 464 -64 432 -64
WIRE -144 32 -144 -64
WIRE -96 32 -144 32
WIRE 80 32 80 0
WIRE 80 32 48 32
WIRE -256 96 -256 -64
WIRE 80 128 80 32
WIRE 432 160 432 -64
WIRE -32 176 -160 176
WIRE 16 176 -32 176
WIRE 160 224 80 224
WIRE -32 240 -32 176
WIRE -160 272 -160 256
WIRE 160 272 160 224
WIRE -160 288 -160 272
WIRE -256 400 -256 176
WIRE -160 400 -160 368
WIRE -160 400 -256 400
WIRE -32 400 -32 320
WIRE -32 400 -160 400
WIRE 160 400 160 352
WIRE 160 400 -32 400
WIRE 432 400 432 240
WIRE 432 400 160 400
WIRE 528 400 432 400
FLAG 464 -64 Vout
FLAG -160 272 Vin
FLAG -256 400 0
SYMBOL npn 16 128 R0
SYMATTR InstName Q1
SYMATTR Value 2N3904
SYMBOL pnp 128 0 M270
SYMATTR InstName Q3
SYMATTR Value BCW68F
SYMBOL res 16 -80 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R3
SYMATTR Value 1
SYMBOL res -176 160 R0
WINDOW 3 -26 67 Left 0
SYMATTR Value 10
SYMATTR InstName R5
SYMBOL res 0 16 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R6
SYMATTR Value 100
SYMBOL voltage -256 80 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value 40
SYMBOL voltage -160 272 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V2
SYMATTR Value PULSE(.7 1.7 .01 300m 100m 10m 500m)
SYMBOL res 416 144 R0
SYMATTR InstName R2
SYMATTR Value 15
SYMBOL res 144 256 R0
SYMATTR InstName R1
SYMATTR Value 20
SYMBOL diode -16 48 R270
WINDOW 0 32 32 VTop 0
WINDOW 3 0 32 VBottom 0
SYMATTR InstName D1
SYMATTR Value 1N4148
SYMBOL res -48 224 R0
SYMATTR InstName R4
SYMATTR Value 100k
TEXT -288 504 Left 0 !.tran .5

========================= CurrAmpMOSFET.asc ============================

Version 4
SHEET 1 880 680
WIRE -80 -64 -256 -64
WIRE 32 -64 0 -64
WIRE 432 -64 128 -64
WIRE 464 -64 432 -64
WIRE 48 0 48 -16
WIRE 80 0 48 0
WIRE -256 32 -256 -64
WIRE -240 32 -256 32
WIRE -128 32 -160 32
WIRE -32 32 -64 32
WIRE 80 32 80 0
WIRE 80 32 32 32
WIRE -256 96 -256 32
WIRE 80 128 80 32
WIRE 432 160 432 -64
WIRE -32 176 -160 176
WIRE 16 176 -32 176
WIRE 16 208 16 176
WIRE 32 208 16 208
WIRE 160 224 80 224
WIRE -32 240 -32 176
WIRE -160 272 -160 256
WIRE 160 272 160 224
WIRE -160 288 -160 272
WIRE -256 400 -256 176
WIRE -160 400 -160 368
WIRE -160 400 -256 400
WIRE -32 400 -32 320
WIRE -32 400 -160 400
WIRE 160 400 160 352
WIRE 160 400 -32 400
WIRE 432 400 432 240
WIRE 432 400 160 400
WIRE 528 400 432 400
FLAG 464 -64 Vout
FLAG -160 272 Vin
FLAG -256 400 0
SYMBOL res 16 -80 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R3
SYMATTR Value 1
SYMBOL res -176 160 R0
WINDOW 3 -26 67 Left 0
SYMATTR Value 10
SYMATTR InstName R5
SYMBOL res -144 16 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R6
SYMATTR Value 1k
SYMBOL voltage -256 80 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value 35
SYMBOL voltage -160 272 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V2
SYMATTR Value PULSE(2.8 4.8 .01 300m 100m 10m 500m)
SYMBOL res 416 144 R0
SYMATTR InstName R2
SYMATTR Value 10
SYMBOL res 144 256 R0
SYMATTR InstName R1
SYMATTR Value 1k
SYMBOL res -48 224 R0
SYMATTR InstName R4
SYMATTR Value 100k
SYMBOL pmos 128 -16 M270
SYMATTR InstName M1
SYMATTR Value FDS4885C_P
SYMBOL nmos 32 128 R0
SYMATTR InstName M2
SYMATTR Value IRL3915
SYMBOL diode -128 48 R270
WINDOW 0 32 32 VTop 0
WINDOW 3 0 32 VBottom 0
SYMATTR InstName D1
SYMATTR Value 1N4148
SYMBOL diode -32 48 R270
WINDOW 0 32 32 VTop 0
WINDOW 3 0 32 VBottom 0
SYMATTR InstName D3
SYMATTR Value 1N4148
TEXT -288 504 Left 0 !.tran .5

 

[Chris]

On Jan 28, 10:30 pm, "panfilero" <panfil...@gmail.com> wrote:

Hello

I need to deliver a variable current between 0-2 Amps to a small load
(15 Ohms).... At first I was thinking about building a current
amplifier..... but after investigating that route again, i think, it's
too difficult to build.

Then I heard about adjustable voltage regulators. And looking through
the datasheet of an LM117, I noticed it had a curcuit example it
called: "Precision Current Limiter" where the output current is
controlled by a potentiometer and can be varied from 0 to 1.65 Amps.

I'm not sure if this is a variable constant current source, but it
kinda sounds like it to me, is anyone familiar with this circuit?

In the "Precision Current Limiter" circuit the current is controlled
by a potentiometer, but I need to control the current with a variable
voltage (between 0 - 5 V), is there such a thing as a voltage
controlled resistor? So that I could use that in this circuit?

any help is greatly appreciated,
thank you
Joshua

Hi, Joshua. You're saying you need to provide 0-2ADC to a 15 ohm load
(30V compliance) which is controlled by a voltage source. The
simplest way to do this is with a floating load (neither side of the
load connected to circuit common). Given that, you can do the whole
thing, including perfboard, with Radio Shack parts like this (view in
fixed font or M$ Notepad):

' + VCC
' | Iout = 0-2A
' | ---> +
' '------o
' VCC
' + .------o
' Vin | | -
' 0-2V ___ |\| |
' o-|___|-o----o-------|+\ ___ |/
' 750 | | | >--o--|___|--| TIP120
' .-. |.1uF.--|-/ | 220 |>
' 220| | --- | |/| --- |
' | | --- | | --- |
' '-' | | === | .01uF |
' | === | GND | ___ |
' | GND '--------o--|___|----o
' | 4.7k |
' | .-.
' | 0.22 ohm | |
' | 5 Watt | |
' | '-'
' |______________________________|
' |
' ===
' GND

(This cookbook circuit is courtesy of the estimable Mr. Winfield Hill
at s.e.d.)

With a 30V supply, you'll be seeing maximum power dissipation at the
transistor when I(out)=1A and V(load) = 15V. That means the other 15V
will be dissipated by the darlington transistor, giving you a
transistor power dissipation of 15 watts. Be sure to provide a really
good heat sink for your transistor if you don't want to let the magic
smoke out.

The op amp is another consideration. You'll need an op amp which can
accept input voltages down to the negative supply rail to accept 0V
input. You could do worse than use 1/2 of an LM358. But be careful
not to have the supply voltage for the op amp exceed 32V.

Hope this has been of help.

Good luck
Chris

 

[Del Cecchi]

PeteS wrote:

Tim McCaffrey wrote:

In article <45bf1bb9$0$18833$9b4e6d93@newsspool4.arcor-online.net>,
maerchenprinz@arcor.de says...

Hi all,

I wonder what is curently state-of-the art in serial high-speed
transmission and what are the prevailing data rates? I know about
some SerDes in the gigabit-per-second range but I cannot imagine if
10 Gbps are really a challenge or the applied method or if it's 1
Gbps (or something in between)...?
I recently heard about some 60 GHz in the mobile communication sector
and 10 Gbit Ethernet but as far as I know there are those multi-level
modulation methods (like QAM for example) that are able to provide 10
Gbit bandwidth with a bitrate of some Mbps (is that correct?).
I'm not interested so much in those higher modulation methods (nor in
optical transmission) but in the baseband communication where bitrate
= clockrate, i.e. the line rate. What can be efficiently transmitted
today electrically (over wire or PCB)? What is the prevailing
technology of those circuits, is it CMOS or are there alternatives?
I am a senior electrical engineer and unfortunately did not manage to
keep up-to-date. After googling all night I'm really depressed
because I finally couldn't find an unambiguous answer.
Maybe some guys in the silicon-business or practitioners know the
anser and are willing to share there knoledge with me?

Best regards
Geronimo

The fastest signaling over copper that I'm (being a software guy, and
not involved in bleeding edge hardware development) aware of (in
production) is 3Gig SAS/SATA cables. I'm not sure what the "baud" of
the protocol is.

Perhaps Infiniband is faster?

- Tim


Well, one of the architects of InfiniBand posted right above you

The 1.2 spec has details for 2.5, 5 and 10Gb/s signaling per pair,
although as I recall from the discussions we had 10Gb/s was not easily
realisable on 'ordinary' materials at the time the 1.2 spec was being
written.

Cheers

PeteS

(VHDL and CAD groups deleted)

It can be done now. IBM has a serdes core in 90nm CMOS that will
operate at 10Gb+ per second.

Fibre Channel now has a 4Gb version that is pretty common, and 10G (or
maybe it's 8G) is coming along.

the original 10G ethernet was 4 lanes at 3.125G.

At 10Gps, normal fiberglass boards can have problems with dielectric
absorbtion. Some versions are better than others. And alternative
materials are better still.


--
Del Cecchi
"This post is my own and doesn’t necessarily represent IBM’s positions,
strategies or opinions.”

 

[PeteS]

Del Cecchi wrote:

PeteS wrote:
Tim McCaffrey wrote:

In article <45bf1bb9$0$18833$9b4e6d93@newsspool4.arcor-online.net>,
maerchenprinz@arcor.de says...

Hi all,

I wonder what is curently state-of-the art in serial high-speed
transmission and what are the prevailing data rates? I know about
some SerDes in the gigabit-per-second range but I cannot imagine if
10 Gbps are really a challenge or the applied method or if it's 1
Gbps (or something in between)...?
I recently heard about some 60 GHz in the mobile communication
sector and 10 Gbit Ethernet but as far as I know there are those
multi-level modulation methods (like QAM for example) that are able
to provide 10 Gbit bandwidth with a bitrate of some Mbps (is that
correct?).
I'm not interested so much in those higher modulation methods (nor
in optical transmission) but in the baseband communication where
bitrate = clockrate, i.e. the line rate. What can be efficiently
transmitted today electrically (over wire or PCB)? What is the
prevailing technology of those circuits, is it CMOS or are there
alternatives?
I am a senior electrical engineer and unfortunately did not manage
to keep up-to-date. After googling all night I'm really depressed
because I finally couldn't find an unambiguous answer.
Maybe some guys in the silicon-business or practitioners know the
anser and are willing to share there knoledge with me?

Best regards
Geronimo

The fastest signaling over copper that I'm (being a software guy, and
not involved in bleeding edge hardware development) aware of (in
production) is 3Gig SAS/SATA cables. I'm not sure what the "baud" of
the protocol is.

Perhaps Infiniband is faster?

- Tim


Well, one of the architects of InfiniBand posted right above you

The 1.2 spec has details for 2.5, 5 and 10Gb/s signaling per pair,
although as I recall from the discussions we had 10Gb/s was not easily
realisable on 'ordinary' materials at the time the 1.2 spec was being
written.

Cheers

PeteS

(VHDL and CAD groups deleted)

It can be done now. IBM has a serdes core in 90nm CMOS that will
operate at 10Gb+ per second.

Fibre Channel now has a 4Gb version that is pretty common, and 10G (or
maybe it's 8G) is coming along.

the original 10G ethernet was 4 lanes at 3.125G.

At 10Gps, normal fiberglass boards can have problems with dielectric
absorbtion. Some versions are better than others. And alternative
materials are better still.

FC is probably 4g - I had one of the early versions running 3 years ago.
The biggest issue is not the serdes as much as the board materials; go
beyond FR4-xx (13 is pretty good) and you're in the realm of exotic
prices, if not materials.

It's the price that's the issue, not the technology, but that's been a
common statement for the last few decades

I have no doubt that once the more exotic PCB material pricing gets
lower and more stable that we'll see more of the really highspeed cores
and serdes in common use.

Cheers

PeteS

 

[PeteS]

Del Cecchi wrote:

PeteS wrote:
Tim McCaffrey wrote:

In article <45bf1bb9$0$18833$9b4e6d93@newsspool4.arcor-online.net>,
maerchenprinz@arcor.de says...

Hi all,

I wonder what is curently state-of-the art in serial high-speed
transmission and what are the prevailing data rates? I know about
some SerDes in the gigabit-per-second range but I cannot imagine if
10 Gbps are really a challenge or the applied method or if it's 1
Gbps (or something in between)...?
I recently heard about some 60 GHz in the mobile communication
sector and 10 Gbit Ethernet but as far as I know there are those
multi-level modulation methods (like QAM for example) that are able
to provide 10 Gbit bandwidth with a bitrate of some Mbps (is that
correct?).
I'm not interested so much in those higher modulation methods (nor
in optical transmission) but in the baseband communication where
bitrate = clockrate, i.e. the line rate. What can be efficiently
transmitted today electrically (over wire or PCB)? What is the
prevailing technology of those circuits, is it CMOS or are there
alternatives?
I am a senior electrical engineer and unfortunately did not manage
to keep up-to-date. After googling all night I'm really depressed
because I finally couldn't find an unambiguous answer.
Maybe some guys in the silicon-business or practitioners know the
anser and are willing to share there knoledge with me?

Best regards
Geronimo

The fastest signaling over copper that I'm (being a software guy, and
not involved in bleeding edge hardware development) aware of (in
production) is 3Gig SAS/SATA cables. I'm not sure what the "baud" of
the protocol is.

Perhaps Infiniband is faster?

- Tim


Well, one of the architects of InfiniBand posted right above you

The 1.2 spec has details for 2.5, 5 and 10Gb/s signaling per pair,
although as I recall from the discussions we had 10Gb/s was not easily
realisable on 'ordinary' materials at the time the 1.2 spec was being
written.

Cheers

PeteS

(VHDL and CAD groups deleted)

It can be done now. IBM has a serdes core in 90nm CMOS that will
operate at 10Gb+ per second.

Fibre Channel now has a 4Gb version that is pretty common, and 10G (or
maybe it's 8G) is coming along.

10G is being touted as 'the next big thing' by the marketdroids is the
hope of getting people to upgrade. Not a whole lot of uptake yet, though.

the original 10G ethernet was 4 lanes at 3.125G.

Uses the same POP4 for optical transmission as the IB spec called for
for 4x lanes.

At 10Gps, normal fiberglass boards can have problems with dielectric
absorbtion. Some versions are better than others. And alternative
materials are better still.

Absorption is the major loss, of course. On dense multilayer (2.4mm, 16
layers for instance) 100 diff tracks are rather narrow and skin effect
losses are quite high which is something we haven't got around yet;
fortunately they increase more as a root function than linear, of
decreasing track width (within limits, of course).

Cheers

Peter Smith

'As I am no longer employed by Infinicon/Silverstorm/Qlogic my
statements have nothing to do with their opinions'