I'm starting to evaluate AD7124-8.
Only to be sure, I would know if I can safely make a measure in unipolar mode using AVSS as negative analog input.
For example, by configuring AINP = 00000b (AIN0) and AINM = 10001b (AVSS).
Yes, AVSS can also be used as input because it is routed to the multiplexer internally when selected. However, please take in to consideration the Ain voltage limits when the input is buffered or un buffered. For un buffered you can use AVSS-0.05V as minimum but for buffered you have a minimum of AVSS+0.1 V for the buffer headroom.
Did you read my last post? I used "Reply to original post" by mistake, so maybe you missed it.
Yes, since your AIN- is just directly connected to AVSS you can leave it un-buffered.
I have one last question on this topic:
Should I do the same "trick" (enabling buffer only on positive input) also for the reference inputs, when the negative reference is at AVSS level and positive reference is not a low impedance input? And more specifically, is disabling the buffer on negative input the only option, when using the internal bandgap or AVDD (both internally referenced to AVSS, if I'm not wrong) as reference inputs?
Sorry for late response. Yes internal reference and AVDD are referenced to AVSS so you can leave your negative reference input un-buffered.
Hi Jellenie, thank you for reply.
Is there any problem if I enable the buffer only for the AIN+ positive input, leaving the AIN- negative input (that I'll connect to AVSS, so a low impedance source) un-buffered?
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