Oznog
Active Member
I distinctly recall hearing that an op-amp's input should not have a voltage on it if the op-amp is not powered- many, many years ago. IIRC, they said it would damage it.
I have a situation where I may need to power down an op-amp, and the output must go to 0v. However, one input I cannot switch off.
The circuit is a simple differential shunt regulator. When Vin>Vref, it turns on an output transistor. That is all it does, really.
Why would the input be a problem? Is there a protection diode that shunts the pin to the Vdd rail, thus powering the amp from the input itself?
I have a situation where I may need to power down an op-amp, and the output must go to 0v. However, one input I cannot switch off.
The circuit is a simple differential shunt regulator. When Vin>Vref, it turns on an output transistor. That is all it does, really.
Why would the input be a problem? Is there a protection diode that shunts the pin to the Vdd rail, thus powering the amp from the input itself?