Other Parts Discussed in Thread: ADS1278-HT, , OPA211, OPA2333, THS4521, ADS1278, OPA2333P
Hi There
i'm designing a high temperature PCB using two ADS1278-HT daisy chained together (16 channels) in frame sync mode, TDM mode, 1MHz clock. Low frequency input signal 0-8Hz, 0-5V centred around 2.5V. System level accuracy is 16 bits
due to PCB space issues i'd like to drive the ADS1278-HT directly from the OPA2333-HT.
My understanding is that delta sigma ADCs over sample at a rate related to the ADC input clock and thus the internal switched capacitor network can be switched quite quickly even for a low bandwidth application
As mentioned above i'd like to use the OPA2333-HT because of its great DC performance, wide input common mode, wide output swing. The concern is its very low bandwidth 350kHz.
Even with this limitation i think its suitable for my application - ADC clock is 1MHz, ADC set up is low speed, with a divide by 40 clkdiv. Thus i think the the actual switch capacitor of the ADC is thus 25kHz (1MHz/40) ??
so even with the 350kHz bandwidth of the OPA2333-Ht it should be fine to drive the ADS1278-HT - if somebody could confirm?
Note: i wasn't really sure if this is an ADC or OP amp question so a similar question is also posted on the ADC forum
https://e2e.ti.com/support/data-converters/f/73/t/869955
Note: I've looked at the HEAT evaluation schematics and op amps such as the OPA211 or THS4521 seem to be used to drive the ADC - the reason i'm trying to avoid these is mainly due to input common mode problems. I could use them but i's also need opa2333 for input common mode and level shifting reasons and PCB real estate is a big problem thus i'd like to use only the dual packed OPA2333-Ht if possible
kind regards
Martin