Qualcomm Incorporated

Baiying Yu

Nihit Bajaj

Troy L Stockstad

Hua Guan

Cheong Kun

Eric Ian Mikuteit

Mark D Zimmerman

Disclosed is battery charging circuit having a first detection circuit and a second detection circuit for detecting when to terminate an activated voltage collapse protection operation. The first detection circuit may be an analog design and the second detection circuit may include digital circuitry.

Method and system for voltage collapse protection

The described apparatus and methods may include a first shifting stage configured to receive a signal having an upper power rail at a first voltage level and a lower power rail at a second voltage level, the first shifting stage configured to shift the upper power rail from the first voltage level to a third voltage level while maintaining the lower power rail at the second voltage level. The apparatus and methods may also include a second shifting stage coupled to the first shifting stage and configured to shift the lower power rail from the second voltage level to a fourth voltage level while maintaining the upper power rail at the third voltage level, the second shifting stage further configured to transmit the signal having the upper power rail at the third voltage level and the lower power rail at the fourth voltage level.

Compact low power level shifter for dual rail

A battery monitoring circuit is described. The battery monitoring circuit includes a high counter that increments when a sense voltage measurement is above a threshold. The battery monitoring circuit also includes a low counter that increments when the sense voltage measurement is below the threshold. The battery monitoring circuit further includes state machine circuitry coupled to the high counter and to the low counter. The battery monitoring circuit additionally includes open circuit voltage monitoring circuitry coupled to the state machine circuitry. The battery monitoring circuit also includes resistance monitoring circuitry coupled to the state machine circuitry.

Battery monitoring circuit

A method and apparatus for providing a temperature sensing loop used in connection with a current sensing component, such as a BATFET, in order to compensate for variations in the BATFET's resistance due to temperature variations. The temperature sensing loop detects a temperature of the BATFET and regulates the gate voltage of the BATFET based on the detected temperature in order to compensate for changes in the BATFET's resistance. The temperature sensing feedback loop maintains the BATFET at a constant resistance for current sensing through negative feedback control. The BATFET and temperature sensing loop can be provided as components of an on-chip fuel gauging application for a UE.

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Santa Clara, CA, United States of America

Baiying Yu