Patent ID: 7911262

Claim:
A compensation circuit, for compensating an external supply voltage, the compensation circuit comprising: an operational amplifier, having a bias voltage as a first input of the operational amplifier, and a second input; a first PMOS pair, coupled to the output of the operational amplifier and the external supply voltage, where the output of the first PMOS pair is the second input of the operational amplifier; a second PMOS pair, coupled to the output of the operational amplifier and the external supply voltage, where the output of the second PMOS pair is an output voltage of the compensation circuit, and is equal to the input voltage −χΔV; a first NMOS circuit, coupled to the first and second PMOS pair by means of a blend connection, and coupled to the external supply voltage, a reference voltage, and a nominal voltage, for providing an output voltage equal to the reference voltage—the nominal voltage/3−χΔV; and a second NMOS circuit, coupled to the first NMOS circuit and the external supply voltage, for providing an output voltage equal to the external supply voltage/3.