Part Number: OPA837 Other Parts Discussed in Thread: OPA625 , TIDA-01055 I was wondering about the common-mode input range of the OPA837 when used as a reference buffer for an ADC.
The TIDA-01055 compares the OPA625 with the OPA837 as a lower power option…
So Kevin, in your current circuit with the OPA725 inverting gain of -1 to generate the -2.5V, that op amp output with no series R and no cap at the VREFN pin will see a sampling glitch due to the closed loop output impedance of the op amp that looks inductive…
Hey Frank,
There was quite a lot of composite reference buffer circuit work going on some time back on a few of the SAR ADC demo designs, One such is here where the idea is you get the precision with the front end amplifier and support the sampling current…