Post Go back to editing

I want to use ADA4075 for a differential input that could have a maximum of 10V differential voltage.

In the datasheet, I see the absolute maximum rating for Differential Input Voltage is ±1.2 V

What does this mean? The Inputs should have a difference not more than  ±1.2 V? how can I consider it in my design? The inputs are ±5V.

The input could have a maximum of 10V differential voltage.
[edited by: mehran at 7:38 AM (GMT 0) on 29 Apr 2020]

## Top Replies

• Hi mehran,

What does this mean?

This amplifier has diode protection between the inputs and if the differential input voltage is sufficient to directly bias these diodes, a significant current will flow through the inputs, which should be limited to a safe level.

how can I consider it in my design?

Regards,

Kirill

This is what I designed and tested with ADA4075 practically. Also in the datasheet, the maximum common-mode voltage has been not defined, please also help me with it.

• Hi mehran,

It should be clear that you are using a differential configuration, here the differential input voltage of the circuit is not equal to the voltage between the inputs of the op amp and can significantly exceed it. Due to the action of negative feedback, the voltage between the inputs of the op amp is close to zero.

If I understand correctly, you are using a supply voltage lower than +/- 15 V and you are interested in the allowable range of common-mode input voltages. For the + / - 5 V case, you can extract useful information from this graph

Common-mode voltage can be + / - 3 V. This is 2 volts lower than the supply voltage, and in the case of a supply voltage of + / - 15 V, the common-mode voltage is 2.5 V lower. Focus on these numbers.

Regards,

Kirill

• Thank you, Kirill.
Now it is clear for me and It is really useful.