Hello,
I am using texas instrument's part number INA2133U and OPA 131 to build the constant current source. The following link will take you to the circuit and data sheet ( page 13, figure 16). The inverting input of the amplifier is grounded.
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I tested the circuit for Leakage current and with zero input voltage , load resistor of value 100kohm, R = 50kohm and rail voltages of +/-
15volts, I am getting current in the range of 1 to 10 micro amp, which is undesirable for my application. The questions are as follows
- Do I need offset trimming like the data sheet discussed it on page number 9?
- Is there any other way to stop this leakage current?
The desirable leakage current range is less than 1 micro amp.
Please advice!
John