Forums Search for: DAC
DAC resolution vs. smoothing filter cutoff-freq
inUsually 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.
A lowpass filter for a DAC
inHi All, I am trying to work out the likely phase lag for a lowpass filter whose job is to take out the notches from a DAC. The DAC is 12...
Hi All, I am trying to work out the likely phase lag for a lowpass filter whose job is to take out the notches from a DAC. The DAC is 12 bit and will be generating a 400Hz sinewave. It will be driven at around 250x i.e. 100kHz. So the fundamental to filter out will be 100kHz. I am not good at maths but doing some digging around, it looks like a simple RC has a 45 deg phase shift at th...
Deglitching a DAC
inAny 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
inWe 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
inI 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?
inMany 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
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 ...
strange DAC
inI need an isolated DAC. I could just generate a PWM thing, isolate it, and lowpass filter on the high side. But we could also generate...
I need an isolated DAC. I could just generate a PWM thing, isolate it, and lowpass filter on the high side. But we could also generate a delta-sigma bit stream, which has advantages. If d-s, I might want to reclock it before lowpass filtering to get clean, fast edges. But then I could drive several d-flops. https://www.dropbox.com/s/0d7x6l6isyoldva/ML_DS_Dac.jpg?raw=1 The analog signal...
DC Coupled Soundcard DAC Mod
inI 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
inHi 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
inOK, 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
inAre 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
inHi, 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
inI'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?
inWhich 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
inHas 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
inWhere 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
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
inDoes 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
inThe 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 ...