US 9,541,989 B2 · Power transfer estimation

Abstract

A power conversion system includes a power transfer estimator that is operable to provide a determination of the cumulative amount of power transferred through the power supply, without additional sensing elements and at extremely low power levels, and to provide such determinations periodically over potentially long periods of time commensurate with the lifetime of a limited power source such as a battery. In a power conversion system operating in a discontinuous conduction mode (DCM), the power transfer estimator determines the charge transferred during each switching cycle, and the total number of switching cycles, to calculate the cumulative amount of power transferred. The power transfer estimator is optionally operable to calculate a value for the inductance to be used in the determination of the cumulative amount of power transferred through the power supply.

Claims6

Dependent claims

A circuit for estimating power transfer, comprising

a power switch for selectively coupling an input terminal of an inductor to a voltage source;
an accumulator for generating a switching metric in response to the actuation of the power switch;
and
a processor operable to determine an estimate of power transferred from the input terminal of the inductor to an output pin of the inductor, wherein the power transfer estimation is determined in response to an inductance value of the inductor, a voltage of the voltage source, and the switching metric;
a differential voltage amplifier that is operable to generate a single-ended voltage in response to a voltage developed across a source and drain of the power switch;
and
a differentiator that is operable to generate a derivative of the generated singled-ended voltage.

4 more elements

Dependencies are inferred from the claim text.

Power transfer estimation

Life of this patent

Power transfer estimation

Life of this patent

Abstract

Claims6