SBOS475K March 2009 – November 2023 INA210-Q1 , INA211-Q1 , INA212-Q1 , INA213-Q1 , INA214-Q1 , INA215-Q1
PRODUCTION DATA
As with any difference amplifier, the INA21x-Q1 common-mode rejection ratio is affected by any impedance present at the REF input. This concern is not a problem when the REF pin is connected directly to most references or power supplies. When using resistive dividers from the power supply or a reference voltage, buffer the REF pin by an op amp.
In systems where the INA21x-Q1 output can be sensed differentially, such as by a differential input analog-to-digital converter (ADC) or by using two separate ADC inputs, the effects of external impedance on the REF input can be cancelled. Figure 6-4 shows a method of taking the output from the INA21x-Q1 family of devices by using the REF pin as a reference.