daniel442
Junior Member level 2
Hi all, I'm having troubles designing this circuit which supposed to be a BandGap circuit with op-amp topology (instead of current mirrors).
in theory, the op-amp supposed to force V2=Vd using a negative feedback. in simulation you can see that Vd is not equal to V2 (~70mV difference) and if I continue to simulate IR3,IR2 which supposed to be equal as well (I0 in theory) there is also some mismatch and off course V_ref is no const. over temperatures...
This circuit is rather simple in his theory and I think that the op-amp parameters are wrong. I've used it from ahdllib (which I am not really familiar with) and configure it as an ideal op-amp (high Rin, low Rout, high Gain).
appreciate any help.
in theory, the op-amp supposed to force V2=Vd using a negative feedback. in simulation you can see that Vd is not equal to V2 (~70mV difference) and if I continue to simulate IR3,IR2 which supposed to be equal as well (I0 in theory) there is also some mismatch and off course V_ref is no const. over temperatures...
This circuit is rather simple in his theory and I think that the op-amp parameters are wrong. I've used it from ahdllib (which I am not really familiar with) and configure it as an ideal op-amp (high Rin, low Rout, high Gain).
appreciate any help.