PWM controllers... shopping

[sea moss]

Seems like every time I start a new power design, I waste a bunch of time looking for the ideal PWM controller.

At the end of the day I'd really like to have the simplest IC possible to handle just the PWM function, and I provide my own error amp, gate driver, and reference externally. The ideal part would look like this: oscillator set by resistor, comparator non-inverting input, and pulse out. Plus Vdd and ground equals 5 pins only! Does anything like this exist?

I've also been checking out the famous TL494, and MC34063 since I have never used them. Does anyone here have horror stories from these parts that I can't infer from the datasheets?

Another one I discovered is MCP1632, pretty simple but not quite what I'm looking for. Vdd=6V max for example, kind of sucks. I do like how they use a 50uA current source as the reference pin, so you set Vref with a resistor or drive from low-impedance source, nice.
http://ww1.microchip.com/downloads/en/DeviceDoc/20005254A.pdf

 

[bitrex]

On 4/10/2020 8:16 PM, bitrex wrote:

On 4/10/2020 7:19 PM, sea moss wrote:
Seems like every time I start a new power design, I waste a bunch of
time looking for the ideal PWM controller.

At the end of the day I'd really like to have the simplest IC possible
to handle just the PWM function, and I provide my own error amp, gate
driver, and reference externally.  The ideal part would look like
this: oscillator set by resistor, comparator non-inverting input, and
pulse out.  Plus Vdd and ground equals 5 pins only!  Does anything
like this exist?

I've also been checking out the famous TL494, and MC34063 since I have
never used them.  Does anyone here have horror stories from these
parts that I can't infer from the datasheets?

Another one I discovered is MCP1632, pretty simple but not quite what
I'm looking for.  Vdd=6V max for example, kind of sucks.  I do like
how they use a 50uA current source as the reference pin, so you set
Vref with a resistor or drive from low-impedance source, nice.
http://ww1.microchip.com/downloads/en/DeviceDoc/20005254A.pdf




You can design your own if you want using something like the
Silego/Dialog GreenPAK OTP mixed-signal PLC:

https://www.dialog-semiconductor.com/configurable-mixed-signal

They have a GUI system-designer it's pretty nice. Their prices are p.
good they'll program the chips with your design probably like 30 cent
per in quantities of thousands last I looked.

Last I heard Apple is doing that for their switching controllers they
want to roll their own vs. off-the-shelf integrated types from the major
manufacturers.

 

[sea moss]

ATTiny13A, 1k program memory, two PWM channels, 10 bit ADC, 20MHz clock.
can do all sorts of stuff with that for 40 cent in 100s

Yeah but it seems like overkill to have C code that just performs a comparator function... plus I wonder how much jitter you would get from using that 10 bit ADC

 

[sea moss]

> I can't get to a 5 pin device, but I bet I can do that in a 48 pin QFN using an FPGA. ICE5LP1K-SG48ITR50, under $3.00 qty 100.

You would need an FPGA with an ADC input. If you already had one on the board, then you could get this PWM block for free.

 

[sea moss]

You can design your own if you want using something like the
Silego/Dialog GreenPAK OTP mixed-signal PLC:

https://www.dialog-semiconductor.com/configurable-mixed-signal

I have used Greenpaks, I really like them. Great for glue logic. Not sure if their analog blocks are up to this task, though. I'll have a browse at their current devices, it's been a few years.

 

[bitrex]

On 4/10/2020 7:59 PM, Ricky C wrote:

On Friday, April 10, 2020 at 7:19:36 PM UTC-4, sea moss wrote:
Seems like every time I start a new power design, I waste a bunch of time looking for the ideal PWM controller.

At the end of the day I'd really like to have the simplest IC possible to handle just the PWM function, and I provide my own error amp, gate driver, and reference externally. The ideal part would look like this: oscillator set by resistor, comparator non-inverting input, and pulse out. Plus Vdd and ground equals 5 pins only! Does anything like this exist?

I've also been checking out the famous TL494, and MC34063 since I have never used them. Does anyone here have horror stories from these parts that I can't infer from the datasheets?

Another one I discovered is MCP1632, pretty simple but not quite what I'm looking for. Vdd=6V max for example, kind of sucks. I do like how they use a 50uA current source as the reference pin, so you set Vref with a resistor or drive from low-impedance source, nice.
http://ww1.microchip.com/downloads/en/DeviceDoc/20005254A.pdf

I can't get to a 5 pin device, but I bet I can do that in a 48 pin QFN using an FPGA. ICE5LP1K-SG48ITR50, under $3.00 qty 100.

There's not much in the control world that can't be done primarily digitally these days.

ATTiny13A, 1k program memory, two PWM channels, 10 bit ADC, 20MHz clock.
can do all sorts of stuff with that for 40 cent in 100s

 

[Ricky C]

On Friday, April 10, 2020 at 7:19:36 PM UTC-4, sea moss wrote:

Seems like every time I start a new power design, I waste a bunch of time looking for the ideal PWM controller.

At the end of the day I'd really like to have the simplest IC possible to handle just the PWM function, and I provide my own error amp, gate driver, and reference externally. The ideal part would look like this: oscillator set by resistor, comparator non-inverting input, and pulse out. Plus Vdd and ground equals 5 pins only! Does anything like this exist?

I've also been checking out the famous TL494, and MC34063 since I have never used them. Does anyone here have horror stories from these parts that I can't infer from the datasheets?

Another one I discovered is MCP1632, pretty simple but not quite what I'm looking for. Vdd=6V max for example, kind of sucks. I do like how they use a 50uA current source as the reference pin, so you set Vref with a resistor or drive from low-impedance source, nice.
http://ww1.microchip.com/downloads/en/DeviceDoc/20005254A.pdf

I can't get to a 5 pin device, but I bet I can do that in a 48 pin QFN using an FPGA. ICE5LP1K-SG48ITR50, under $3.00 qty 100.

There's not much in the control world that can't be done primarily digitally these days.

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209

 

[bitrex]

On 4/10/2020 7:19 PM, sea moss wrote:

Seems like every time I start a new power design, I waste a bunch of time looking for the ideal PWM controller.

At the end of the day I'd really like to have the simplest IC possible to handle just the PWM function, and I provide my own error amp, gate driver, and reference externally. The ideal part would look like this: oscillator set by resistor, comparator non-inverting input, and pulse out. Plus Vdd and ground equals 5 pins only! Does anything like this exist?

I've also been checking out the famous TL494, and MC34063 since I have never used them. Does anyone here have horror stories from these parts that I can't infer from the datasheets?

Another one I discovered is MCP1632, pretty simple but not quite what I'm looking for. Vdd=6V max for example, kind of sucks. I do like how they use a 50uA current source as the reference pin, so you set Vref with a resistor or drive from low-impedance source, nice.
http://ww1.microchip.com/downloads/en/DeviceDoc/20005254A.pdf

You can design your own if you want using something like the
Silego/Dialog GreenPAK OTP mixed-signal PLC:

<https://www.dialog-semiconductor.com/configurable-mixed-signal>

They have a GUI system-designer it's pretty nice. Their prices are p.
good they'll program the chips with your design probably like 30 cent
per in quantities of thousands last I looked.

 

[bitrex]

On 4/10/2020 8:27 PM, sea moss wrote:

You can design your own if you want using something like the
Silego/Dialog GreenPAK OTP mixed-signal PLC:

https://www.dialog-semiconductor.com/configurable-mixed-signal

I have used Greenpaks, I really like them. Great for glue logic. Not sure if their analog blocks are up to this task, though. I'll have a browse at their current devices, it's been a few years.

I have a client whose final design is going to be about the size of a
postage stamp thanks to those, he was sighing and saying "well I guess
if we can get it to perhaps 3" by 3" with today's tech that's just what
I'll have to work with"...Heh

 

On Fri, 10 Apr 2020 16:19:31 -0700 (PDT), sea moss
<danluster81@gmail.com> wrote:

Seems like every time I start a new power design, I waste a bunch of time looking for the ideal PWM controller.

At the end of the day I'd really like to have the simplest IC possible to handle just the PWM function, and I provide my own error amp, gate driver, and reference externally. The ideal part would look like this: oscillator set by resistor, comparator non-inverting input, and pulse out. Plus Vdd and ground equals 5 pins only! Does anything like this exist?

I've also been checking out the famous TL494, and MC34063 since I have never used them. Does anyone here have horror stories from these parts that I can't infer from the datasheets?

Another one I discovered is MCP1632, pretty simple but not quite what I'm looking for. Vdd=6V max for example, kind of sucks. I do like how they use a 50uA current source as the reference pin, so you set Vref with a resistor or drive from low-impedance source, nice.
http://ww1.microchip.com/downloads/en/DeviceDoc/20005254A.pdf

You can make a decent analog-to-PWM converter with an RRIO opamp or
comparator and a cap and three resistors.




--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard

 

[Ricky C]

On Friday, April 10, 2020 at 8:25:46 PM UTC-4, sea moss wrote:

I can't get to a 5 pin device, but I bet I can do that in a 48 pin QFN using an FPGA. ICE5LP1K-SG48ITR50, under $3.00 qty 100.

You would need an FPGA with an ADC input. If you already had one on the board, then you could get this PWM block for free.

Oh, how would that work?

You can construct an ADC in any FPGA with differential inputs which is pretty much all of them.

--

Rick C.

-- Get 1,000 miles of free Supercharging
-- Tesla referral code - https://ts.la/richard11209

 

[Ricky C]

On Friday, April 10, 2020 at 8:24:41 PM UTC-4, sea moss wrote:

ATTiny13A, 1k program memory, two PWM channels, 10 bit ADC, 20MHz clock.
can do all sorts of stuff with that for 40 cent in 100s

Yeah but it seems like overkill to have C code that just performs a comparator function... plus I wonder how much jitter you would get from using that 10 bit ADC

I don't recall learning about the engineering metric "overkill". A solution should be judged on the merits, not biases.

My concern with a small MCU is the processing limitation, but if it does the job, fine.

Your characterization of this as a comparator seems a bit short of the mark. Isn't this the bulk of the control algorithm? If it were just a comparator why not just use a comparator?

--

Rick C.

+ Get 1,000 miles of free Supercharging
+ Tesla referral code - https://ts.la/richard11209

 

[bitrex]

On 4/10/2020 8:24 PM, sea moss wrote:

ATTiny13A, 1k program memory, two PWM channels, 10 bit ADC, 20MHz clock.
can do all sorts of stuff with that for 40 cent in 100s

Yeah but it seems like overkill to have C code that just performs a comparator function... plus I wonder how much jitter you would get from using that 10 bit ADC

IDK if the ATTiny13 has it but a number of devices from that line have
hardware dead-time generators on the PWM outputs so the manufacturer
clearly expected it could be used in a switch-controller role

 

[bitrex]

On 4/10/2020 8:24 PM, sea moss wrote:

ATTiny13A, 1k program memory, two PWM channels, 10 bit ADC, 20MHz clock.
can do all sorts of stuff with that for 40 cent in 100s

Yeah but it seems like overkill to have C code that just performs a comparator function... plus I wonder how much jitter you would get from using that 10 bit ADC

the line has some other occasionally useful features in certain
applications like the ones with differential ADCs can sense high-side up
to several volts over the uP's own supply rail without additional hardware

 

[Tim Williams]

Why do you need an external error amp, or all the other things? Internal
ones are so nice.

Here are some starters, plus bonus memes:
https://imgur.com/gallery/M1S0DbI

TL494 is fine, but it's a big chip for most purposes, and isn't current mode
as such. Very hungry, something like ~10mA operating. It can be used for
average current mode pretty easily (use one err amp for low side current
sense feedback, disable the other), but you do need to add an external
voltage error amp. (In an isolated circuit, this is the secondary side
TL431 or whatever, which works out nicely.)

MC34063 is a hysteretic controller, and not even a good one at that. The CS
pin reduces oscillator frequency in an odd way.

At least the NCP3064 has proper cutoff under current limiting conditions; I
don't feel bad using it, but I would still prefer something with lower
output ripple.

TPS54xxx and others are good for local supplies. Hundreds to select from;
picking any single one would be futile. Parametric search on ti.com,
Digi-Key and others is the way to go.

Tim

--
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Design
Website: https://www.seventransistorlabs.com/

"sea moss" <danluster81@gmail.com> wrote in message
news:4fb6d1db-b955-40ab-b8f7-5156a39f6e3d@googlegroups.com...
Seems like every time I start a new power design, I waste a bunch of time
looking for the ideal PWM controller.

At the end of the day I'd really like to have the simplest IC possible to
handle just the PWM function, and I provide my own error amp, gate driver,
and reference externally. The ideal part would look like this: oscillator
set by resistor, comparator non-inverting input, and pulse out. Plus Vdd
and ground equals 5 pins only! Does anything like this exist?

I've also been checking out the famous TL494, and MC34063 since I have never
used them. Does anyone here have horror stories from these parts that I
can't infer from the datasheets?

Another one I discovered is MCP1632, pretty simple but not quite what I'm
looking for. Vdd=6V max for example, kind of sucks. I do like how they use
a 50uA current source as the reference pin, so you set Vref with a resistor
or drive from low-impedance source, nice.
http://ww1.microchip.com/downloads/en/DeviceDoc/20005254A.pdf

 

[boB]

On Fri, 10 Apr 2020 16:19:31 -0700 (PDT), sea moss
<danluster81@gmail.com> wrote:

Seems like every time I start a new power design, I waste a bunch of time looking for the ideal PWM controller.

At the end of the day I'd really like to have the simplest IC possible to handle just the PWM function, and I provide my own error amp, gate driver, and reference externally. The ideal part would look like this: oscillator set by resistor, comparator non-inverting input, and pulse out. Plus Vdd and ground equals 5 pins only! Does anything like this exist?

I've also been checking out the famous TL494, and MC34063 since I have never used them. Does anyone here have horror stories from these parts that I can't infer from the datasheets?

Another one I discovered is MCP1632, pretty simple but not quite what I'm looking for. Vdd=6V max for example, kind of sucks. I do like how they use a 50uA current source as the reference pin, so you set Vref with a resistor or drive from low-impedance source, nice.
http://ww1.microchip.com/downloads/en/DeviceDoc/20005254A.pdf

I guess the big question is, what are you wanting to do with the
controller ?

Sometimes a micro is good enough. Sometimes one of thsoe Greenpaks
are good. I use them.

I also use the UC3843 family of current mode controllers. They are
similar to the Microchip device you linked to but are slightly
different.

Depends on the application. And is it for a product where you would
buy a lot of them ? Or a one off project ?

boB

 

[David Brown]

On 11/04/2020 08:46, boB wrote:

On Fri, 10 Apr 2020 16:19:31 -0700 (PDT), sea moss
danluster81@gmail.com> wrote:

Seems like every time I start a new power design, I waste a bunch of time looking for the ideal PWM controller.

At the end of the day I'd really like to have the simplest IC possible to handle just the PWM function, and I provide my own error amp, gate driver, and reference externally. The ideal part would look like this: oscillator set by resistor, comparator non-inverting input, and pulse out. Plus Vdd and ground equals 5 pins only! Does anything like this exist?

I've also been checking out the famous TL494, and MC34063 since I have never used them. Does anyone here have horror stories from these parts that I can't infer from the datasheets?

Another one I discovered is MCP1632, pretty simple but not quite what I'm looking for. Vdd=6V max for example, kind of sucks. I do like how they use a 50uA current source as the reference pin, so you set Vref with a resistor or drive from low-impedance source, nice.
http://ww1.microchip.com/downloads/en/DeviceDoc/20005254A.pdf




I guess the big question is, what are you wanting to do with the
controller ?

There have been a dozen answers to the OP already, all promoting the
predictable favourite solutions. For any question in electronics, Rick
will inevitably claim an FPGA is the simplest, cheapest and most
flexible solution. John Larkin will want to do it all in analogue
electronics. Bitrex will immediately propose a small microcontroller.
Then they will argue about the pros and cons of these.

Thank you for that breath of fresh air, asking what the thing is
supposed to do. Only once that is figured out, is it possible to look
at ideas for a solution.

Sometimes a micro is good enough. Sometimes one of thsoe Greenpaks
are good. I use them.

I also use the UC3843 family of current mode controllers. They are
similar to the Microchip device you linked to but are slightly
different.

Depends on the application. And is it for a product where you would
buy a lot of them ? Or a one off project ?

boB

 

[bitrex]

On 4/11/2020 9:52 AM, David Brown wrote:

On 11/04/2020 08:46, boB wrote:
On Fri, 10 Apr 2020 16:19:31 -0700 (PDT), sea moss
danluster81@gmail.com> wrote:

Seems like every time I start a new power design, I waste a bunch of
time looking for the ideal PWM controller.

At the end of the day I'd really like to have the simplest IC
possible to handle just the PWM function, and I provide my own error
amp, gate driver, and reference externally.  The ideal part would
look like this: oscillator set by resistor, comparator non-inverting
input, and pulse out.  Plus Vdd and ground equals 5 pins only!  Does
anything like this exist?

I've also been checking out the famous TL494, and MC34063 since I
have never used them.  Does anyone here have horror stories from
these parts that I can't infer from the datasheets?

Another one I discovered is MCP1632, pretty simple but not quite what
I'm looking for.  Vdd=6V max for example, kind of sucks.  I do like
how they use a 50uA current source as the reference pin, so you set
Vref with a resistor or drive from low-impedance source, nice.
http://ww1.microchip.com/downloads/en/DeviceDoc/20005254A.pdf




I guess the big question is, what are you wanting to do with the
controller ?

There have been a dozen answers to the OP already, all promoting the
predictable favourite solutions.  For any question in electronics, Rick
will inevitably claim an FPGA is the simplest, cheapest and most
flexible solution.  John Larkin will want to do it all in analogue
electronics.  Bitrex will immediately propose a small microcontroller.
Then they will argue about the pros and cons of these.

These are....scurrilous accusations!!

Thank you for that breath of fresh air, asking what the thing is
supposed to do.  Only once that is figured out, is it possible to look
at ideas for a solution.

That's the ideal, sure, but often "what do you want to do" is the
hardest question to get a straight answer on, and by the time you get
one and start pondering potential solutions it starts to feel like work
one should be getting paid for. I dunno about other people but I still
optimistically have to do that for another ~25 years before I have a
shot at retirement...

Sometimes a micro is good enough.  Sometimes one of thsoe Greenpaks
are good.  I use them.

I also use the UC3843 family of current mode controllers.  They are
similar to the Microchip device you linked to but are slightly
different.

Depends on the application.  And is it for a product where you would
buy a lot of them ?  Or a one off project ?

boB

 

[Winfield Hill]

bitrex wrote...

... do that for another ~25 years before I have a
shot at retirement...

Is retirement a good thing?


--
Thanks,
- Win

 

[Lasse Langwadt Christense]

lørdag den 11. april 2020 kl. 20.12.06 UTC+2 skrev Winfield Hill:

bitrex wrote...

... do that for another ~25 years before I have a
shot at retirement...

Is retirement a good thing?

a lot of people used to working and the mental exercise that
comes with it, wither and die surprisingly fast after they retire