Convergence error in PSpice for my LDO design

[sohaib342]

pspice power circuit convergence

Hello all. Well this is the problem I am facing. I have designed an LDO by designing an bandgap reference and a differential amplifier. The problem I am having is that when I connect the two pieces together I get a vonvergence error and I am not understanding why because the amplifier and the bandgap work perfect separately. I am attaching a picture of the circuit I am working on. Thank you all in advance.

 

[flatulent]

pspice ldo

Find the bias points from the separate simulations and then put them in as .nodest values in the combined simulation.

 

[hock]

convergence error

make sun circuit of your amp and bandgap referance. ise the sun circuit in your new schematic. look for unsaturated transistors.

BTW whis is your design process? you are using both mos and bipolar transistor.

Hock