In an inverting amplifier configuration, how does the power supply rejection ratio (PSRR) impact the output signal when the supply voltage fluctuates?

The PSRR tells how well an op‑amp can ignore changes in its supply voltage; a higher PSRR means the amplifier’s output stays closer to the ideal value when the supply wiggles. In an inverting amplifier, the output is a scaled version of the input, so any error that creeps in from the supply appears multiplied by the gain. For example, if the supply jumps 1 V and the PSRR is 80 dB (a ratio of 10⁴), the output will shift by about 0. 1 mV, which is negligible compared to a 1 V input. If the PSRR were only 20 dB, the same 1 V supply change would produce a 10 mV error at the output, which could be significant.