Patent ID: 7928703
Filing Date: 2011-04-19
Classification: G01R,H02M

Abstract:
1. An on-chip current-sense system for measuring a magnitude of an output current flowing one of to and from a phase node and through a power transistor, the system comprising: a first sense transistor configured to conduct a first reference current one of to and from the phase node; a second sense transistor configured to conduct a second reference current one of to and from a power rail, the first and second sense transistors being substantially identical and being proportionally matched to the power transistor; an operational transconductance amplifier (OTA) configured to receive the first reference current, the second reference current, and a third reference current that flows one of to and from the phase node and to generate a sense current that is substantially linearly related to the output current in response to the first, second, and third reference currents; and a sense circuit configured to compare the sense current with a predetermined magnitude and to generate an over-current signal in response to the sense current being greater than the predetermined magnitude to indicate an over-current condition associated with the output current.