AMC1350: Need clarity regarding input side connection of AMC1350

Part Number: AMC1350

Hi 

Need clarity regarding the resistor divider network connection at the input of AMC1350. Figure below shows the current schematic for battery voltage sensing.( 0-850). But in our case there is  one requirement as  protection for battery voltage reversal. That is if the battery is connected reversed, at that time also the battery voltage should be sensed properly. Can you confirm whether this connection is proper or not ?Because while testing we are observing oscillation .Tried to give input at the positive side of resistor network alone, then we did not observe any oscillations , but we give input at the negative side oscillations were there. So i doubt the connection at the input of AMC1350.

 image.png

Please verify the connection..

  • Hi Kruthi, 

    Do you have a waveform that describes the oscillations seen? 

    Is the rest of the circuit besides the battery and AMC1350 + Rdiv disconnected when oscillations are seen? 

    Why is there R127 = 51k in series with the negative input? 

    Have you tried removing C58, 10nF at the output of the OPA?