OPA191: To double checking customer's circuit

Paul Yeh

Part Number: OPA191

my customer design OPA191 and need us to double check is their schematic ok or not.

Please help to check.

Atfirst, the AI side input signal voltage range is +/-5V and the OPA191 output should become 0~5V voltage range, so it should act as level shift.

Please suggest.

Thanks

over 5 years ago

0 Raymond Zhang1 over 5 years ago

TI__Guru* 77501 points

Hi Paul,

With 7.5V single supply rail, your input Vcm in OPA191 has to be in the following range. Your input voltage can be ranged from 0-7.5V at V+ pin. Also, please watch out the Voltage output swing requirements shown on p8. of the datasheet.

Your input filter has high pass filter behavior. The input amplitude will be attenuated at -10.42dB or 0.30V/V. If you have 1Vpeak amplitude is placed at input, you will get 0.30V at Vout1 or V+ of OPA191 stage. Is this your input requirement? (10^(-10.42dB/20) = 0.30 V/V). Assume that input amplitude at V+ swings at 7.5Vpp, then the output of OPA191 will be 2.2725Vpp, which means that you are going to achieve 0-1.13Vp swing at the OPA191's output.