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Original question:
Tool/software:
Hi sir,
I am using ADS8634SRGE
In the datasheet, DRIVING ANALOG SIGNAL INPUT section (page No-61) it was mentioned that
"Make sure the driving op amp bandwidth does not limit the signal bandwidth to below the filter bandwidth. In many applications, signal bandwidth may be much lower than filter bandwidth. In this case, an additional low-pass filter may be used at the input of the driving op amp."
I am using AD8479TRZ-EP OP-AMP it has "130 kHz small signal −3 dB bandwidth"
I am using the recommended circuit on page No-61 i.e. the RC filter where R=20Ohm and C=1200PF
Filter Time Constant = R*C=24nS
Filter Bandwidth =6631KHz
Should I calculate Filter bandwidth in such a way that it will below 130KHz?
Hi Rakesh,
How fast do you plan on operating (i.e. what throughput speed) the ADS8364 and what input voltage range do you plan to use? We have a tool in the Analog Engineer's Calculator that helps you pick an appropriate amplifier for driving SAR converters. The ADC SAR Drive tool lets you put in your desired acquisition time and a few parameters from the datasheet. At full speed with 0-5V input range, you would need a ~13MHz bandwidth amplifier to drive the inputs:
