Other Parts Discussed in Thread: TLV2450
I have a customer using the OPA170 in a design, and during prototype testing they ran into the below issue:
We are using the TI OPA170 on a new controller board for the purpose of battery cell measurement. In order to reduce power consumption while the system is asleep, we have a circuit to turn off V+ under MOSFET control. V- supply and a bias voltage into VIN+ remain powered, while VIN- is not.
During final engineering testing, we discovered that there is a negative leakage path across the ESD protection diode structure and the pass diode in the FET to the cell voltage that normally powered V+. This can cause an imbalance between the cells over time.
The OPA170's data sheet shows the diode protection structure below:
We would like to know if there are other pin-compatible TI op-amps (SOT-23) with a different type of ESD clamp that does not pass current from VIN+ to V+. We understand that the TLV2450 uses a different type of clamp, but that op-amp is not compatible.