AD620B: Supply voltage

Document created by analog-archivist Employee on Feb 23, 2016
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I want to use the instrumentation amplifier AD620B with a power supply of 10V
and ground. The operating range of the power supply is denoted with +/-2,3V -
+/-18V in the data sheet. Can i use it although or what will change with this
power supply.


As you might expect, the device powered from 0 to +10V will behave identically
to a +/-5V supply only the input and output voltage ranges will be shifted
according to the new power supplies.

i.e. common mode input voltage range is approximately +1.9V to 8.8V and output
range is 1.1V to 8.8V.

In fact the only pin that is usually connected to GND is the REF pin. This may
cause an additional challenge because
a) you cannot connect REF to either supply rail as its voltage range is -Vs +
1.6V to +Vs -1.6V
b) the pin MUST be driven from a very low impedance otherwise the common mode
rejection of the In Amp will be degraded. This does become a problem if you
need to synthesise a precise mid-supply voltage which has very low ouput
impedance - you usually need an extra op amp to generate this voltage e.g. to
buffer a voltage divider.