DAC resolution vs. smoothing filter cutoff-freq

Started by vkj in sci.electronics.design9 years ago 8 replies
DAC

Usually the smoothing filter after the DAC is supposed to have a cut-off freq.

Usually the smoothing filter after the DAC is supposed to have a cut-off freq.


Deglitching a DAC

Started by Spehro Pefhany in sci.electronics.design8 years ago 93 replies
DAC

Any clever ideas on getting rid of glitches in a high precision DAC output? Update rate is a fixed rate, probably in the 10-100kHz range, and...

Any clever ideas on getting rid of glitches in a high precision DAC output? Update rate is a fixed rate, probably in the 10-100kHz range, and I'd like to keep the glitches (especially variation in glitches) to < < 25ppm, preferably < 5ppm. A S&H with a low charge injection switch?


dac architecture

Started by John Larkin in sci.electronics.design2 years ago 35 replies

We were talking about TCXOs. One measures temperature and drives a varicap through some nonlinear transfer function to get minumum net TC. We...

We were talking about TCXOs. One measures temperature and drives a varicap through some nonlinear transfer function to get minumum net TC. We don't want a digital design (ADC, lookup table or polynomial, DAC) because that might add phase noise. I guess you could use a static polynomial with the equivalent of nonvolatile DPOTS as the coefficients. This occurred to me, not as anything p...


PCIe card with FPGA and DAC

Started by John Larkin in sci.electronics.design5 years ago 8 replies

I got a call from a really nice guy who has a tiny company in the Bahamas. Our gear is too expensive for his application, but it could be...

I got a call from a really nice guy who has a tiny company in the Bahamas. Our gear is too expensive for his application, but it could be done with a PCIe PC-plugin board that has an FPGA and a fast DAC. It would need analog bandwidth in the 30 MHz range, maybe 100M samples/sec or so. He would need help to program the FPGA, since the signal set that he needs to generate is kind of weird, ...


Pease turkey DAC?

Started by Tom Del Rosso in sci.electronics.design9 years ago 10 replies
DAC

Many years ago I read a Pease column in which he told the story of a client who was trying to design a DAC for the video display of an A4 or...

Many years ago I read a Pease column in which he told the story of a client who was trying to design a DAC for the video display of an A4 or A6 aircraft. He had to do environmental testing but it wouldn't fit in the chamber, so he put it in a turkey roasting bag and did it in a regular oven. It was a neat one, but I have never been able to find that column online. Of course I remembe...


radhard multichannel DAC

Started by alb in sci.electronics.design6 years ago
DAC

Hi everyone, I'm looking for a RADHARD multichannel 12bit DAC which can sustain 15krad or thereabout. We have 9 channels to feed and I'd like...

Hi everyone, I'm looking for a RADHARD multichannel 12bit DAC which can sustain 15krad or thereabout. We have 9 channels to feed and I'd like to avoid using 9 individual ICs for obvious reasons (surface, cost, reliability, etc.). A potential candidate if we needed a single channel would have been: DAC121S101QML (12bit/15us 2mW 100krad). Any suggestions? Thanks in advance, Al ...


DC Coupled Soundcard DAC Mod

Started by Ken Morrow in sci.electronics.design5 years ago 20 replies

I want to generate a signal in my computer that has a DC offset and output them to the real world. Unfortunately, the DC offset does not...

I want to generate a signal in my computer that has a DC offset and output them to the real world. Unfortunately, the DC offset does not pass through my soundcard. So I found this "solution" online. http://www.whence.com/soundcard-dc-dac/ What the article does not state is that the large chip on the circuit board gets very hot trying to pump out DC instead of the bipolar signal it...


Digital Analog converter for resonator circuit

Started by chess in sci.electronics.design5 years ago 11 replies

Hi I have dual resonator circuit consists of Inductors, capacitors and resistors. I am generating sine wave with amplitude of 1 from DAC...

Hi I have dual resonator circuit consists of Inductors, capacitors and resistors. I am generating sine wave with amplitude of 1 from DAC and write a frequency sweep function in Matlab however I only get a single resonator response and I am missing the second peak. when I connect 1 ohm or any value less than that in parallel with DAC I am able to get both peaks. I can also get both peak when I am...


dac dithering

Started by John Larkin in sci.electronics.design7 years ago 41 replies

OK, I'm sort of thinking this through. Suppose I have a stream of parallel digital words that represent a waveform. Assume it's audio or...

OK, I'm sort of thinking this through. Suppose I have a stream of parallel digital words that represent a waveform. Assume it's audio or something similar. Further assume that it has an arbitrary number of bits available at an arbitrarily high rate; we can fake the rate by digital interpolation if the raw data stream isn't fast enough. Assume that I want to use a 16 bit DAC but I nee...


Many switches, single line

Started by Bobby Joe in sci.electronics.design9 years ago 9 replies

Are there cheap SPST switches that have built in single wire comm. that can all be hooked up serially? Or is there an efficient method to...

Are there cheap SPST switches that have built in single wire comm. that can all be hooked up serially? Or is there an efficient method to allow for expanding the number of switches easily? I was thinking of a possible DAC like setup but this limits the number of switches and speed and may be error prone. 16 switches would require a 16-bit DAC. What I'd like is a single 1 wire interfac...


DAC buffer with negative VOUT in shutdown state

Started by Piotr Wyderski in sci.electronics.design1 year ago 10 replies

Hi, TL;DR: a precision linear MOSFET pre-driver capable of putting negative voltage on the gate in order to shut the current flow down....

Hi, TL;DR: a precision linear MOSFET pre-driver capable of putting negative voltage on the gate in order to shut the current flow down. Quickly and hard to eliminate spurious noise-induced turn-ons. Detailed: I have a precision unbuffered 16-bit DAC that outputs 0--4.095V. The analog subsystem uses +12/-5V supplies in order to place the opamps (OPA4192) well within the linear re...


MicroController control for switching regulator

Started by RogerN in sci.electronics.design4 years ago 72 replies

I'm wanting to use a microcontroller to control the output of a switching regulator, maybe something like a LM2576 simple switcher. I see the...

I'm wanting to use a microcontroller to control the output of a switching regulator, maybe something like a LM2576 simple switcher. I see the adjustability is on the feedback lead but what's the best way make it adjustable from a microcontroller. I'm guessing the feedback may be used in switching timing, ie, I guess I can't just use a DAC and get an output of 1.23V more than the DAC ...


Your Favorite ARM?

Started by Martin Riddle in sci.electronics.design9 years ago 31 replies
DAC

Which Mfg has the best options for their ARM processors? I've never worked with a ARM, and I was going to play with a Atmel AVR32, but the ARM...

Which Mfg has the best options for their ARM processors? I've never worked with a ARM, and I was going to play with a Atmel AVR32, but the ARM seems to have more features for a buck or two more. Preferable package is LQFP. And not so pricey tools. 12 bit DAC and ADC a plus. Cheers


TI DAC2904 dual DAC

Started by John Larkin in sci.electronics.design4 years ago 3 replies
DAC

Has anyone used the DAC2904? We don't entirely understand the timing. We asked TI for help, and thay said "Oh, that's an old Burr-Brown part,...

Has anyone used the DAC2904? We don't entirely understand the timing. We asked TI for help, and thay said "Oh, that's an old Burr-Brown part, nobody knows much about that." -- John Larkin Highland Technology, Inc jlarkin att highlandtechnology dott com http://www.highlandtechnology.com


Where to get high speed ADC's and DACs

Started by RobertMacy in sci.electronics.design7 years ago 48 replies
DAC

Where do I get 24 bit high speed ADC and DAC systems out to 10MHz? Or, turn around how much digitization can I get out to 100MHz today? 20 ...

Where do I get 24 bit high speed ADC and DAC systems out to 10MHz? Or, turn around how much digitization can I get out to 100MHz today? 20 bits?


Photonic ADC and DAC-good books

Started by AntonF in sci.electronics.design3 years ago
DAC

Hi! Could you recommend good books/materials on: - photonic ADCs and DACs - radio-photonics thanks!

Hi! Could you recommend good books/materials on: - photonic ADCs and DACs - radio-photonics thanks!


LPC1768 ADC

Started by John Larkin in sci.electronics.design9 months ago 6 replies

Does anyone use the LPC176* uPs? I need to know how much current the ADC/DAC VREFP pin uses, and I can't find that anywhere. You'd think they...

Does anyone use the LPC176* uPs? I need to know how much current the ADC/DAC VREFP pin uses, and I can't find that anywhere. You'd think they might spec that. They recommend filtering it, but the eval board uses a ferrite bead. -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtec...


Good hardware, poor software

Started by bitrex in sci.electronics.design3 years ago 68 replies
DAC

The graveyard of audio production equipment is littered with the corpses of products that had rock-solid hardware designed by professionals, but...

The graveyard of audio production equipment is littered with the corpses of products that had rock-solid hardware designed by professionals, but firmware written by nincompoops. It's really frustrating when you buy a blinky-light box that some engineers somewhere likely spent thousands of man-hours on designing the best sounding DAC structure they could for the budget, but then the OS ...


Where do you buy instruments, and who makes 'em?

Started by Tim Wescott in sci.electronics.design9 years ago 20 replies

I need to get a nice audio signal generator. Something that refers back to a crystal, instead of a function generator chip. Preferably...

I need to get a nice audio signal generator. Something that refers back to a crystal, instead of a function generator chip. Preferably something with a DDS and a nice high-accuracy DAC. I have something hacked together on proto board that worked astonishingly well, all things considered -- but it's still hacked together on protoboard, and only changes frequency with a change of a crys...


semiconductor drift

Started by John Larkin in sci.electronics.design6 years ago 52 replies

We have two 8-channel waveform generators that were shipped 4 months ago, and came back because the customer ordered too many or something. We...

We have two 8-channel waveform generators that were shipped 4 months ago, and came back because the customer ordered too many or something. We routinely test anything that comes back, before returning them or returning to stock. What's interesting is that all 16 channels have a negative DC offset. Each channel is a diff-current-output cmos DAC, an opamp diffamp, a passive LC filter, and ...