As a TI Customer, I would like design INA185A4 version
(Gain=200V/V) current sense AMP but I have a couple questions?
Q1 - Customer has found there is one case may that exceed Vout max rating spec as below description can you please help review and give the feedback suggestion?
application case,
Answer
(1)VS connect to 3.3V,
(2) Iload max =22A
(3) unidirectional application (VREF =0V).
(4) Rsense = 1mohm.
Q2 - Base on the Above application. the calculated result of Vout = 4.4V seems out of Vout max rating spec ( out of VS+0.3V = 3.3V +0.3V = 3.6V) is there any risk of this design? Q3 - Should I change connect to 5V for VS power supply?
Answer The absolute maximum here more refers to external sources driving the VOUT pin into these types of voltages. The part itself is incapable of driving itself higher than VS, and in the scenario, you describe the part would saturate against the rail, similar to any op amp. This is safe to do, but obviously the customer would not be able to measure any voltage higher than the saturation point. My recommendation would be to try and develop a solution of the A3 GAIN and a slightly larger shunt to maximize the full scale range utilized while keeping the part within the linear operating range.**
INA185: INA185 VS and VOUT design questions - Amplifiers forum - Amplifiers - TI E2E support forums