# AD8253 spec under +-5V power supply

Document created by analog-archivist on Feb 23, 2016
Version 1Show Document

### Q

Here is one customer wants to know the specification of AD8253 when use +/-5V
power supply. However, the spec table in datasheet is only for +/-15V power
supply.

### A

The specifications at +/-5V should be nearly identical to +/-15V
specifications.  We try to give the customer some insights where we expect
there to be significant differences:  see figures 28-30, 32, 33.
The customer can add the power supply rejection numbers to the offset.   Here's
how:
Customer is going from a total 30V power supply span to a 10V power supply
span.  This is a 20V difference.  So the calculation for max offset would be:
(150 + 900/G) + (20 * (5 + 25/Gain)) = 150 +100 + 900/Gain + 500/Gain = 250 +
1400/Gain
So max offset could be +/-(250 + 1400/Gain) uV
although I think this is pretty conservative.  Offset over temperature should
see a change roughly proportional to the offset change.