Patent ID: 7956679

Claim:
A differential amplifier with offset voltage trimming comprising: at least one current supply; a differential current to voltage converter having a positive current input node, a negative current input node and a voltage output node, wherein in operation the voltage output node provides an output voltage that is proportional to the difference in current values flowing into the positive current input node and a negative current input node; an offset voltage trimming circuit having a plurality of trimming control inputs, an inverting trimming output, a non-inverting trimming output and at least two trimming inputs coupled to the at least one current supply, the offset voltage trimming circuit further includes a plurality of trimming resistances coupling the inverting trimming output to the non-inverting trimming output, and a plurality of trimming selectors, controllable by a trim code provided to the trimming control inputs, provide for selectively connecting the current supply directly to the non-inverting trimming output whilst selectively connecting the current supply to the inverting trimming output through a first selected group of the trimming resistances; and a differential transistor pair formed by an inverting transistor that couples the inverting trimming output to the positive current input node and a non-inverting transistor that couples the non-inverting trimming output to the negative current input node.