Power supply rejection ratio introduction
The power ripple rejection ratio (PSRR) is the ratio of the input power variation (in volts) to the converter output variation (in volts), usually expressed in decibels. For high-quality D/A converters, when the power supply voltage used by the switching circuit and operational amplifier changes, the output voltage is minimal. Usually the ratio of the percentage of the full-scale voltage change to the percentage of the power supply voltage change is called the power supply ripple rejection ratio.