Power monitoring in integrated circuits

Abstract

Power monitoring is needed in most electrical systems, and is crucial for ensuring reliability in everything from industrial and telecom applications, to automotive and consumer electronics. Power monitoring of integrated circuits (ICs) is also essential, as today ICs exist in most electrical and electronic systems, in a vast range of applications. Many ICs, including power ICs, have functional blocks across the chip that are used for different purposes. Measuring circuit block currents in both analog and digital ICs is important in a wide range of applications, including power management as well as IC testing and fault detection and analysis. For example, the presence of different kinds of faults in IC circuit blocks during IC fabrication causes the currents flowing through these circuit blocks to change from the expected values. There has been general interest in monitoring currents through different circuit blocks in an attempt to identify the location and type of the faults. Previous works on non intrusive load monitoring as well as on power-line communications (PLCs) provide motivation for the work presented here. The techniques are extended and used to develop a new method for power monitoring in ICs. Most solutions to the challenge of measuring currents in different circuit blocks of the IC involve adding circuitry that is both costly and power consuming. In this work, a new method is proposed to enable individual measurement of current consumed in each circuit block within an IC while adding negligible area and power overhead. This method works by encoding the individual current signatures in the main supply current of the IC, which can then be sensed and sampled off-chip, and then disaggregated through signal processing. A demonstration of this power monitoring scheme is given on a modular discrete platform that is implemented based on the UC3842 current-mode controller IC, which can also be used for educational purposes.