Part Number: OPA191
Hi team,
My customer wants to find a single-ended output op amp with Vcom, the performance and SIZE should be close to OPA191.
The figure below is customer's original design. The Vcom of R202 and R203 is 2.5V, and the signal is offset by 2.5V. They have found that we can’t design this way
For example: THS4551 has VCOM.
Thanks
Hi Paul,
Q: The Vcom of R202 and R203 is 2.5V, and the signal is offset by 2.5V. They have found that we can’t design this way
2.5V in Vcm needs to be low impedance device, such as voltage source or another buffered output, otherwise, there will be impedance interference at the input.
I am not clear what are your input and output requirements, so I presented three ways to configure Vcm per your circuit.
Enclosed is a simulation in the last example.
If you have additional questions, please let me know.
Best,
Raymond
Raymond,
one more question about this device's application, can OP191 use non-symmetrical power source?
see below circuit, +Vs id 7.5V bit -Vs is -2.5V.
Thanks
Hi Paul,
can OP191 use non-symmetrical power source?
Yes, it will work fine. Below is the power rail and Vcm and Vout swing requirements.
/cfs-file/__key/communityserver-discussions-components-files/14/OPA191-Vcm-input-range-11232020.TSC
If you have other questions, please let us know.
Best,
Raymond
