AnsweredAssumed Answered

OP400 Max Input Voltage

Question asked by BuckeyeDemon on Jul 25, 2011
Latest reply on Jul 25, 2011 by harryh

I'm using the OP400 amplifier in what is basically a classic non-inverting buffer application.

 

The positive input is subject to large voltage transients where I have 1N5806 diodes connected between the input and positive/negative supply rails of the device.

 

Given the large input transients, the diodes will clamp the voltage to approximately 1V beyond the power rails of the amplifier.

 

The OP400 datasheet in the Absolute Maximum Ratings section indicates the Absolute Maximum Input voltage is equal to the Supply Voltage.

 

In the above circuit, the input voltage could be 1V beyond the power supply voltage.

 

How do I protect this input from damage?  It's common practice to insert a series resistor on the input to limit possible input current to less than 5 mA.

 

Would this sort of protection (series limiting input resistor) be acceptable for the OP400?

Outcomes