Patent ID: 7737718

Claim:
A power supply assembly for finding an error against a set voltage by feeding back an applied voltage applied to a load, and applying a predetermined voltage to the load by causing an output amplifier to increase and decrease amperage to be fed to the load on the basis of the error, wherein the output amplifier comprises an input terminal receiving the set voltage and a power supply terminal, wherein the power supply assembly is provided with a voltage converter causing a voltage level of a power supply voltage supplied to the power supply terminal of the output amplifier to follow up a voltage level of the set voltage, wherein the voltage level of the power supply voltage of the output amplifier is variable, wherein the voltage converter comprises: a level-shift circuit for receiving the set voltage and adding a bias voltage to the voltage level of the set voltage to generate a reference voltage; and a DC-DC converter connected to the level-shift circuit and receiving the generated reference voltage, and wherein the DC-DC converter is connected to the power supply terminal of the output amplifier and outputs the power supply voltage to the output amplifier on the basis of the reference voltage from the level-shift circuit.