Were currently using LM10H/883 in a 4-20ma output pressure sensor prototype. We are getting non-linear temp curves (S curves) across the temp range of -60F to 250F (See Chart Below). The input to the LM10 (Output from bridge) is linear. Our test data indicates that this is coming from the LM10H. No improvements were seen when changing Q1 to 2N2907A or when we removed the Cap/overvoltage circuit (Ci, R9, CR1, & TVS1). Increasing R3 & R4 to 9.09K to help isolate sensor loading did not correct this issue.
Excitation = 26VDC (Pins B & A) , Current to the sensor bridge is constant current (U1B & Q2) = 2.1ma.
Any insight to the possible cause of this is much appreciated.
Best Regards,
Bryan
