What are the differences between the ADPD4000 vs the ADPD4100 regarding performance/advantages/features.
Thanks for reaching out. They are pin-to-pin compatible but we recommend ADPD4100 for new designs which is the latest generation. I will list a couple points regarding your question:
1. ADPD4100 has a TIA Ceiling detection feature, where it detects that the TIA is getting close to its saturation point through two voltage comparators at the output terminals of the TIA. ADPD4000 doesn't have such a mechanism. This feature warns the user for saturation or potential saturation in dynamic environments, and the user can change the TIA gain to adjust to the environment changes as the microcontroller will receive an interrupt regarding this.
2. ADPD4100 has a lower noise floor, therefore the noise is reduced.
2. Peak SNR of ADPD4100 is much higher, ADPD4100 can provide 100+ dB DC SNR, whereas ADPD4000 peak DC SNR is around 90+ dB. Depending on the mode, you could get 5-10+ dB increase in the peak SNR.
3. Power consumption of ADPD4100 could be significantly smaller than ADPD4000 depending on the settings. There is no typical number but depending on the use case, you may expect to get 20%-30% reduction. Therefore ADPD4100 is more power efficient.
4. ADPD4100 has a lower standby power for 1 MHz clock.
5. ADPD4100 has an improved PSRR.
6. ADPD4100 has an enhanced chopping capability to eliminate low frequency noise more.
7. ADPD4100 has a subsampling feature, where you can define different sampling frequencies for different timeslots, which allows significant power savings for applications that require a lower sampling frequencies. For example, you can set the sampling frequency to 300 Hz for ECG application, and for a PPG application in another timeslot, you can set the subsampling rate to (let's say) 3 which will allow the PPG application sampling frequency to be 100 Hz. This will reduce the power consumption of PPG application to 1/3 of the original power consumption without subsampling enabled. ADPD4000 doesn't have this feature.