Patent ID: 7239195

Claim:
A negative current generator for an amplifier circuit, the amplifier circuit including a current source transistor having a first current terminal coupled to a first supply terminal, a control terminal receiving a first bias voltage and a second current terminal coupled to an input node, said negative current generator comprising: a shunt transistor having a control terminal and having first and second current terminals for coupling to the first and second current terminals, respectively, of the current source transistor; first and second mirror transistors, each having a control terminal, a first current terminal coupled to the first supply terminal and a second terminal coupled to a voltage node, wherein said control terminal of said first mirror transistor receives a second bias voltage; a current bias device, coupled between said voltage node and a second supply terminal, that draws a constant current from said voltage node; and an amplifier having a first input receiving a reference voltage, a second input coupled to said voltage node, and an output coupled to said control terminals of said shunt and second mirror transistors.