Offset problems with AD8054

       Hi. I have the above scheme using the AD8054 op amp. If I ground the JP2 pins I have 0.15 V at the 1, 2 and 3 pins. When I raised pin 3 in the air and connected it directly to GND I still had 0.15V at 1 and 2 pins. If it is not clear in the picture, 2 and 3 pins are inputs and 1 is output. Supply is +/- 5V. What ever voltage there is at JP2 pins there is always an 0.15V extra voltage at the output. Could anyone please help me? Thank you.

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  •        Thank you again for your quick reply.These are the measurements that you asked. At pin 4 there is 5V and at pin 11 there is -5V. At the other +inputs (pins 5,10 and 12) there is no signal and the outputs are: 0.17V at pin 7, 0.16V at pin 8 and 0.16V at pin 14( all -inputs are in short-circuit with the outputs).

         When I applied 1.45V instead of 0V at the far end of R34 there was 0.32V al pins 1,2 and 3.

         I also tried with a brand new AD8054 to test it separately on a test board. I applied 1.47V at pin 3 and at pins 1 and 2, wich were wired together, there was 1.79V.

        Thank you very much.

Reply
  •        Thank you again for your quick reply.These are the measurements that you asked. At pin 4 there is 5V and at pin 11 there is -5V. At the other +inputs (pins 5,10 and 12) there is no signal and the outputs are: 0.17V at pin 7, 0.16V at pin 8 and 0.16V at pin 14( all -inputs are in short-circuit with the outputs).

         When I applied 1.45V instead of 0V at the far end of R34 there was 0.32V al pins 1,2 and 3.

         I also tried with a brand new AD8054 to test it separately on a test board. I applied 1.47V at pin 3 and at pins 1 and 2, wich were wired together, there was 1.79V.

        Thank you very much.

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