Hi,
I am working on a circuit based on shunt resistors measurement. My circuit has 3 stages, with 2 stages composed of a shunt resistor in parallel with an analog switch, to avoid too big voltage drops. I use 3 shunt resistors to provide a wide range of measurement for my circuit. The analog switches are controlled by a comparator, which is itself controlled by the shunt resistor of the next stage. When the current is high enough, the voltage across the next shunt resistor is high enough to put the comparator in a high state, which enables the analog switch, so the first shunt resistor is bypassed. This application is functional when I simulate the circuit.
Because the analog switch still has a parasite voltage, I want to add a 2:1 multiplexer to select the stage where I want to measure voltage with my OpAmp. Unfortunately, when I add a multiplexer (I used all the different models of 2:1 TI muxes on Pspice), I get an error and the simulation fails.
Can you help me to figure out why and to simulate my circuit ? You can find attached the Pspice file.
Thank you by advance. test shunts.opj
TEST SHUNTS.DSN
Regards,
Ghilain
