Patent ID: 7728654

Claim:
A current generator, comprising: a chopper stabilization operational amplifier, comprising a first input terminal, a second input terminal, and an output terminal, wherein the chopper stabilization operational amplifier is adapted for eliminating a low frequency noise and an offset voltage; a transistor, comprising a gate coupled to the output terminal of the chopper stabilization operational amplifier, a first source/drain coupled to the first input terminal of the chopper stabilization operational amplifier, and a second source/drain serving as a current output terminal of the current generator; an impedance unit comprising a first terminal coupled to the first source/drain of the transistor, and a second terminal coupled to a first voltage, wherein the impedance unit is a second transistor, the current generator further comprising: a third transistor, comprising a first source/drain, a second source/drain and a gate, wherein the first source/drain of the third transistor coupled to the second input terminal of the chopper stabilization operational amplifier, the gate of the third transistor coupled to the second source/drain of the third transistor, and the second source/drain receiving a reference current; and a fourth transistor, comprising a first source/drain coupled to the first voltage, a second source/drain coupled to the first source/drain of the third transistor, and a gate coupled to a gate of the second transistor and the gate of the third transistor.