I see Microchip are making this absurd claim in AN2785 "World's Fastest Embedded Interleaved 12-bit ADC Using PIC32MZ and PIC32MK Families": Has anyone here evaluated the H7 ADCs and is free to provide some results? PS. Hopefully ST will fix this soon but I'm not holding my breath. Yes it's your responsibility to verify the performance of a part that you have selected meets the claims but the datasheet should include all the relevamt data in an accessable form and you should expect it to be reasonably close to reality if it isn't labelled 'preliminary'. You could expend a lot of time and money in a project before discovering the impact of that footnote which could easily render that project unviable. In the case of the STM32H7 parts I think that the huge disparity between the headline claim of 3 x (up to) 3.6MSPS ADCs and the 1MSPS for one ADC that we might now expect for most devices is almost fraudulent given that the training presentation clearly shows they know how the ADCs perform yet the recently released (November) STM32H750 datasheet almost totally ignores the package impact apart from that seemingly innocuous footnote. Microchip came a bit of a cropper with their PIC32MZ ADCs which didn't remotely meet expectations, but they did admit to that and downgraded the datasheet specs. MCU ADC specs are always a bit of a minefield and to their credit ST do provide some of the most detailed ADC specs. Use a LQFP208 package (and also, presumably, the cheap LQFP100 version) and it seems you only get 1MSPS!! That presumably is for the direct channels so maybe the 'fast' channels are even worse? Maybe that presentation is out of date but I doubt it's far off the mark. The TFBGA240 apparently only achieves 2.5MSPS, which to be fair is still pretty good, but presumably only if you are only using one ADC. But this presentation provides some insight: Specifically page 11: There's nothing in the presentation that shows how the number of ADCs in use effects performance but the package has a massive impact you can get 3.6MSPS but only using the UFBGA169 which only provides one differential direct channel. The values for other packages and multiple ADCs may be different.' Alarm bells!!! Don't bother searching the datasheet for elucidation. These values are valid for UFBGA176+25 and one ADC. But check the small print a bit more closely - specifically: '3. So far, not too bad a compromise - an extra $1 or so for a BGA version, but maybe you can use the extra IO. Unfortunately the cheapest TFBGA240 is the STM32H750XB at $4.77 compared to $3.69 for the LQFP100 STM32H750VB that you might have been planning to use. 65mm UFBGA176 packages so you can at least use cheap PCB fabricators. Why on earth didn't they provide the ADC12 direct channels instead since the whole point of them is for high performance? Ok, the TFBGA240 package is. But there's a 'gotcha' of course and in this case only the 240 pin BGA package provides 4 direct channels - the 169 and 176 pin BGA, WLCSP and all LQFP packages only provide the 2 direct channels to ADC3. But one pair of direct channels goes to both ADC1 and 2 allowing you to sample one signal at 7.2MSPS with ADCs 1 and 2 in dual interleaved mode so technically you can sample at 3 x 3.6MSPS but with only 2 signals which might suit your needs. Hmm - but to get 13.2 bit ENOB performance you have to use the ADCs in differential mode which means that only two signals can use these direct channels so the third would have to use a 'fast channel' at 2.9MSPS max. Hmm, so what are they? They are 2 or 4 (depending on package) dedicated IO pads with low impedance paths to the ADCs selectable by 4 bits in the SYSCFG_PMCR register. Fair enough, but with the revision V datasheet comes the new qualification that this applies to 'direct channels'. THD -90dB Impressive Ok, the LPC4370 has an 80MSPS 12 bit ADC with approx 10 bit ENOB but 2.5V, Tj = 90C (rather than 125C). The STM32H7 has possibly the best (specified) fast ADCs of any MCU with 3 x 3.6MSPS 16 bit SAR ADCs with hardware oversampling: ENOB 13.2 DNL 14bit equiv (differential linearity, equivalent to a 14bit ADC with 1 bit DNL) INL 13bit equiv (integral linearity).
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