SBOS999A March 2022 – October 2022 INA851
PRODUCTION DATA
In the default unity-gain configuration, the INA851 fully differential amplifier output stage uses 5-kΩ feedback resistors between the OUT+ and OUT– outputs and the inverting and noninverting inputs, respectively. However, the INA851 also features internal 1.25-kΩ feedback resistors between those inputs and the G02+ and G02– pins. By shorting the G02+ pin to the OUT+ pin, and the G02– pin to the OUT– pin, the amplifier is placed in an attenuating gain of 0.2 V/V.
Additionally, access directly to the inverting and noninverting inputs of the fully differential amplifier is provided through the FDA_IN– and FDA_IN+ pins, respectively. This option allows circuit designers to add external feedback capacitors in parallel with the internal feedback resistors to implement noise filtering or noise-gain shaping techniques. These pins can also be used to implement customized attenuating gains for the output stage. Do not treat these pins as outputs, nor use the pins to source or sink current.