**Part Number:** INA186

I have a group of current sensors all connected to the same +Vs/2 output reference voltage (Vref) source

Due to wiring, a maximum of 1 Ohm series source resistance (Rs) has to be taken into account

The value R of the four resistors used in the differential output amplifier of the INA186A1 are not specified in the data sheet

If Rs << R, then Vout = Vref - Vref x Rs/2R + Vcm x Rs/2R

Vcm is the first stage common output voltage. The error is zeroed if Vcm = Vref. The worst case is met when Vcm is close to either Vs rails.

At Vs = 5 V, the output voltage error is less than 0.125 mV if R is greater than 10 kOhms (with Rs = 1 Ohms), meaning 0.005 mV input error at a gain of 25.

This could be acceptable for a 12 bit acquisition system as it only represents 50 ppm of the of 2.5 V full scale

Please confirm the lowest possible R value for the INA186A1 and the impact of 1 Ohm source resistance on Vref

Thank you

Francois