Hi,
I am designing a BGR and PSRR simulations confuse me.
I simulate PSRR+ by adding a dc source(amplitude=5V) and a ac source(amplitude=5V) at VDD and then PSRR+ is about -70dB.
Similarly, I simulate PSRR- by adding a dc source(amplitude=0V) and a ac source(amplitude=5V) at VSS and then PSRR- is about 0dB.
spice commands:
VDD VDD gnd DC=5 AC=1
VSS VSS gnd DC=0
.............for PSRR+ simulation
VDD VDD gnd DC=5
VSS VSS gnd DC=0 AC=1
.............for PSRR- simulation
So, I don't know if the simulations are right. If the simulations are all right, how to
improve PSRR- of the BGR?