Patent ID: 7310016

Claim:
Amplifier circuitry comprising: (a) an input chopping circuit for chopping first and second input signals; (b) a first differential transconductance stage having first and second input terminals coupled to corresponding outputs of the input chopping circuit, the first differential transconductance stage also having first and second outputs; (c) a first folded cascode stage including i. first and second current source transistors each having a first electrode, a second electrode, and a control electrode, the first electrodes of the first and second current source transistors being connected to the first and second outputs, respectively, of the transconductance stage, the second electrodes of the first and second current source transistors being coupled to a first supply voltage, ii. first and second cascode transistors each having a first electrode, a second electrode, and a control electrode, iii. a first un-chopping circuit having first and second inputs connected to the first and second outputs, respectively, of the first differential transconductance stage, and first and second outputs coupled to the second electrodes of the first and second cascode transistors, respectively, and iv. a first chopper-stabilized gain boost amplifier having first and second inputs coupled to the first and second outputs of the first differential transconductance stage and an output coupled to the control electrode of the second cascode transistor; and (d) an output stage having a first input coupled to the first electrode of the second cascode transistor, wherein the input chopping circuit, the first differential transconductance stage, the first folded cascode stage, and the output stage form a first operational amplifier.