Apple Inc.
Non-invasive on-chip power measurement technique

Abstract:

An apparatus includes an integrated circuit that includes an in-circuit power switch coupled to a power supply node, a functional circuit coupled between the in-circuit power switch and a ground node, a test circuit, and a test power switch coupled to the test circuit, wherein the test power switch is a replica of the in-circuit power switch. The test circuit is configured to determine characteristics of the test power switch, and to measure a voltage difference across the in-circuit power switch. The test circuit is also configured to use the characteristics of the test power switch and the voltage difference to determine a power consumption of the functional circuit.