Hello
I have several questions for device
When the upper OP-AMP is a normal Vcc input and the lower OP-Amp is an abonormal Vcc input, the voltages at points 1 and 2 are not equal. Can leakage occur at the input of OP-AMP when the components power is not supplied?
If I use the LT1014MJB(DIP) package type,can the voltages at points 1 and 2 be the same?
Are the input characteristics of SMD Type and dip type devices different?
Rocio,
For one, your circuit configuration has a positive feedback and thus the output will be stuck at one of the rails regardless of the input signal - see below.
Therefore, to make any sense, you need to change the circuit to use a negative feedback so the output follows the input - see below.
Having said that, each I/O pin has a ESD protection diode to its rails (see below). Thus, powering down lower op amp will result in the input current, AM1, based on the input signal: AM1 =~ (VG1-0.6V) / 12k. Therefore, the issue is NOT a leakage current but simply forward-bias current through one of the ESD diodes.
