Current sensing circuitry

Abstract

A differential sensing system for sensing a current through a circuit element of a circuit, the differential sensing system comprising: a first current sense path having an input for coupling to a first node of the circuit element, the first current sense path comprising a first plurality of replica devices; a second current sense path having an input for coupling to a second node of the circuit element, the second current sense path comprising a second plurality of replica devices, wherein the second plurality is equal to the first plurality; a first cross-coupling switch operable to couple the input of the first current sense path to the second plurality of replica devices; a second cross-coupling switch operable to couple the input of the second current sense path to the first plurality of replica devices; differential amplifier circuitry having first and second inputs, wherein the differential amplifier circuitry is configured to output a differential replica current pair indicative of the current through the circuit element; and a controller, wherein the differential sensing system is operable in a chopping mode to perform a chopping operation in which: the first cross-coupling switch and a replica device of the first current sense path are controlled by the controller to couple the first input of the differential amplifier circuitry to the input of the first current sense path in a first phase of a chopping operation and to the input of the second current sense path in a subsequent phase of the chopping operation; and the second cross-coupling switch and a replica device of the second current sense path are controlled by the controller to couple the second input of the differential amplifier circuitry to the input of the second current sense path in the first phase of the chopping operation and to the input of the first current sense path in the subsequent phase of the chopping operation.

Dependencies are inferred from the claim text.