System for accurate battery run time estimation utilizing voltage capture and coulomb counting

Abstract

A disclosed embodiment is a low-cost, low-power system for run time estimation of a battery utilized by an electronic device. The system comprises a voltage capture circuit configured to measure a voltage of the battery and a coulomb counting circuit configured to measure a charge of the battery. Additionally, the voltage capture circuit is configured to measure an open-circuit voltage of the battery during a sleep mode, or battery voltage during an operation mode, and the coulomb counting circuit is configured to measure a discharge of the battery during the sleep mode, or a change or discharge of battery during an operation mode. The voltage capture circuit comprises a sample-and-hold circuit and an analog-to-digital converter, while the coulomb counting circuit comprises a sigma-delta converter, a comb filter, and a digital accumulator. The voltage capture circuit and the coulomb counting circuit are coupled through a power management unit to a microprocessor configured to estimate battery run time in the electronic device.

Dependencies are inferred from the claim text.