Clarification on circuit - LT1630

[Slasher_44]

Hi ,

I'm a newbie on analog design . I was hoping someone can give me more info on the attached circuit .

I feel the first op-amp acts as a differential amplifier and the second one I'm confused with the capacitors in feedback path , whether its a filter or integrator / differentiator or they are there just for the impedance ...

I tried measuring on the boards , two versions on the opamp pins , I noticed something like the IC's(LT1630 on different boards same circuit ) giving different output for same inputs . I know opamps try to make both their inputs same , but I cant see how they give different output for same input .

Pin number 3 is a constant dac drive , approx 4.5 Volts . Sense +/- are power supply sense pins .

Also it could be appreciated if some one can tell me a godd practical oriented e-book for gaining more insight on opamps .

Thanks

 

[LvW]

The first opamp has no power supply shown (single or dual supply?)
The 2nd opamp has no dc feedback and single supply. Cannot work.
Where does the circuit comes from?

 

[Slasher_44]

Hi LvW ,

Both op-amps(U18 A and U18 B) in same 8-PIN SOIC. So have same supply as the U18A . Yea , the series cap is reason for my doubt also . Its a working circuit and I have the boards with me . I'm trying to debug it to recreate a similar setup .

The circuit is part of a power supply sense circuit . The output of U18A goes to transistor regulator (voltage) and input to U18B is Sense + and Sense - pins .