Which processor with many DAC's & ADC's? - Page 1
Forum section: electronics / general

author: Fran3
author_rank: Newbie
timestamp: July 12, 2023, 03:02:04 pm
content: I'm researching which processor comes with a lot of on board DAC's and ADC's.Many other things have to be ultimately considered...but I wanted to start by just compiling a list of processors with many DAC's & ADC's.Thanks for any help.

author: MasterT
author_rank: Frequent Contributor
timestamp: July 12, 2023, 03:21:21 pm
content: My finding is stm32G474re : 5-ADC & 7-DAC

author: liaifat85
author_rank: Regular Contributor
timestamp: July 12, 2023, 03:50:54 pm
content: You can see the AFE7222EVM board:https://www.ti.com/tool/AFE7222EVM

author: ArdWar
author_rank: Frequent Contributor
timestamp: July 12, 2023, 04:02:42 pm
content: Quote from: MasterT on July 12, 2023, 03:21:21 pmSTM32G4x4 only have 2 externally accessible DAC peripheral, for a total of 3 channels.Quote from: Fran3 on July 12, 2023, 03:02:04 pmAs usual when someone asking for a rather absurd requirements, why?

author: MasterT
author_rank: Frequent Contributor
timestamp: July 12, 2023, 04:13:52 pm
content: Quote from: ArdWar on July 12, 2023, 04:02:42 pmRead RM carefully, there are 6 OPA to buffer DAC, clear?

author: ArdWar
author_rank: Frequent Contributor
timestamp: July 12, 2023, 04:33:20 pm
content: Quote from: MasterT on July 12, 2023, 04:13:52 pmSo that's still 4 DAC. 3 with 2 channel and 1 with single channel.

author: MasterT
author_rank: Frequent Contributor
timestamp: July 12, 2023, 04:47:01 pm
content: Quote from: ArdWar on July 12, 2023, 04:33:20 pmConcept of the "channel" in ST terminology is not known to me. There are 7 DAC's, no multiplexing, no limiting for simultaneous updates all 7 at onesSo I could only guess, that when ST says DAC has 2 channels it simply means two DACs considered as one having two channels if they linked to the same DMA channel and have possibility be updated with one 32-bits DMA push. For "normal" logic it's 7 DACs.

author: Siwastaja
author_rank: Super Contributor
timestamp: July 12, 2023, 04:57:08 pm
content: Yes, in ST's terminology, DAC "channel" does not imply any limitations, AFAIK; they are as good as "separate" DACs. There are only extra advantages, like synchronized update on single write.

author: nctnico
author_rank: Super Contributor
timestamp: July 12, 2023, 04:59:29 pm
content: Quote from: Fran3 on July 12, 2023, 03:02:04 pmYou have to be specific about required accuracy, effective number of bits, impedances, update speeds, etc. There are so many ways to attack this problem. I have designs that use over 32 16-bit ADC channels but the required samplerate is low enough to use analog multiplexers.For DACs the same. You can create many high accuracy DAC channels using PWM or sample & hold circuits using a CMOS buffer opamp (TL074 for example). Yokogawa and Tektronix use these kind of methods in their oscilloscopes to create various offset signals.

author: ArdWar
author_rank: Frequent Contributor
timestamp: July 12, 2023, 05:08:48 pm
content: Quote from: MasterT on July 12, 2023, 04:47:01 pmYes, there are 7 output as each DAC channels are obviously independent of each other analog-wise. It allows for sync update for each channel pairs inside a peripheral module, but the contrary is also true, you can't update only one channel without reloading the whole pair.

author: PCB.Wiz
author_rank: Super Contributor
timestamp: July 12, 2023, 09:32:29 pm
content: Quote from: Fran3 on July 12, 2023, 03:02:04 pmP2X8C4M64P - has 64 smart pins, each of which have DAC and ADC included, so you have any mix of ADC/DAC up to 64

author: SiliconWizard
author_rank: Super Contributor
timestamp: July 12, 2023, 09:40:23 pm
content: Quote from: PCB.Wiz on July 12, 2023, 09:32:29 pmPretty cool chip, although obviously in the "odd" category architecture- and software- wise, so not necessarily for everyone.

author: PCB.Wiz
author_rank: Super Contributor
timestamp: July 12, 2023, 09:48:59 pm
content: Quote from: SiliconWizard on July 12, 2023, 09:40:23 pmThe OP asked for ADC/DAC countsThe P2X8C4M64P has C/BASIC/Assembler/Forth/Spin & probably others I forget, so it is not that different software wise.

author: Shonky
author_rank: Frequent Contributor
timestamp: July 12, 2023, 11:38:58 pm
content: So you don't care about any other spec? Number of bits, conversion rates, INL/DNL, sigma/delta vs SAR, multichannel vs multiplexed, DMA capability etc?i.e. simply quantity over quality?

author: brucehoult
author_rank: Super Contributor
timestamp: July 12, 2023, 11:45:14 pm
content: Quote from: MasterT on July 12, 2023, 03:21:21 pmThe humble ATMega2560 has 16 ADCs and 15 PWMs. No DAC as such. The ADCs are a single converter with a 15 kS/s maximum rate, and an analogue MUX.Whether or not that would suit OP is impossible to say as they didn't give speed or accuracy requirements.

author: james_s
author_rank: Super Contributor
timestamp: July 13, 2023, 01:53:32 am
content: You can use the parametric search on digikey or other supplier to narrow things down. You can also easily pair external ADCs/DACs to whatever microcontroller you want.

author: peter-h
author_rank: Super Contributor
timestamp: July 13, 2023, 10:55:14 am
content: In various avionics products the need for many DACs has been done by creating many PWM outputs, and lowpass filtering them. Very cheap, if the constraints are OK for you. A lot of CPUs have timers which can generate PWM, with great resolution.ADCs... you can use an analog mux. Actually I often find that if a customer wants something with lots of analog inputs, often the application calls for isolation and that is a lot more work.Rather than choose a possibly dead-end CPU it may be better to look at a dedicated chip with lots of inputs, and an SPI interface.

author: mikerj
author_rank: Super Contributor
timestamp: July 13, 2023, 05:05:45 pm
content: ADuCM410, 16 bit 2MSPS ADC with sixteen external channels, some of which can be configured to have a PGA or a variable gain TIA input. Twelve 12 bit DACs, 8 external and others can be used to bias the TIA inputs or set comparator thresholds.

author: peter-h
author_rank: Super Contributor
timestamp: July 14, 2023, 09:30:35 am
content: As so often happens, the OP threw some crumbs into the pond and 1000 ducks are fighting over themNo spec -> no possible advice. There is a vast range of ways to do this.

author: Siwastaja
author_rank: Super Contributor
timestamp: July 14, 2023, 09:35:20 am
content: General advice:Need special peripheral/connectivity X (e.g., three UARTs, or 57 ADC channels, or CAN bus, or 1337 IO pins)The question: Is there a microcontroller which is of familiar enough architecture, does not cost much more than the simpler models, is easily available? If yes, it's better to use that, than to add external ICs. If no - for example if the only microcontroller which satisfies the requirements is of esoteric product family, out of stock everywhere, or costs arm and leg - just use external ICs to extend the functionality.

author: radiolistener
author_rank: Super Contributor
timestamp: July 15, 2023, 11:11:56 am
content: you can use almost any STM32 MCU in order to connect many ADC and DAC. You can use parallel bus multiplexing in order to connect them all into one MCU.