Qualcomm Incorporated

Chuang Zhang

Farsheed Mahmoudi

James Thomas Doyle

Nan Chen

Junmou Zhang

Zhengming Fu

Amirali Shayan Arani

Sassan Shahrokhinia

Yuancheng Christopher Pan

In one embodiment, a method for measuring current comprises generating a sensor current based on a current being measured. The method also comprises converting a combined current into a first frequency, wherein the combined current is a sum of the sensor current and a common-mode current, and converting the first frequency into a first count value. The method further comprises converting the common-mode current into a second frequency, converting the second frequency into a second count value, and subtracting the second count value from the first count value to obtain a current reading.

Low power small area oscillator-based ADC

A circuit including: a three-level buck converter having: a plurality of input switches and an inductor configured to receive a voltage from the plurality of input switches, the plurality of input switches coupled with a first capacitor and configured to charge and discharge the first capacitor; a second capacitor at an output of the buck converter; and a switched capacitor at an input node of the inductor, wherein the switched capacitor is smaller than either the first capacitor or the second capacitor.

Circuits and methods providing three-level signals at a synchronous buck converter

Systems and methods for sensing temperature on a chip are described herein. In one embodiment, a temperature sensor comprises a first transistor having a gate, a second transistor having a gate coupled to the gate of the first transistor, and a bias circuit configured to bias the gates of the first and second transistors such that the first and second transistors operate in a sub-threshold region, and to generate a current proportional to a difference between a gate-to-source voltage of the first transistor and a gate-to-source voltage of the second transistor. The temperature sensor also comprises an analog-to-digital converter (ADC) configured to convert the current into a digital temperature reading.

Low power low cost temperature sensor

A circuit including: a control system for a three-level buck converter, the three-level buck converter including multiple input switches, each of the input switches receiving one of a plurality of different pulse width modulated signals, the control system including: a first clock signal and a second clock signal, the second clock signal being a phase-shifted version of the first clock signal; ramp generating circuitry receiving the first and second clock signals and producing first and second ramp signals, respectively, from the first and second clock signals; a first comparing circuit receiving the first ramp signal and producing a first one of the pulse width modulated signals therefrom; and a second comparing circuit receiving the second ramp signal and producing a second one of the pulse width modulated signals therefrom.

Circuits and methods for controlling a three-level buck converter

An apparatus and method are disclosed for providing efficient operation in a feedback loop having a synchronous buck converter. The synchronous buck converter includes a plurality of individually selectable phases, where each of the phases has a plurality of individually selectable and parallel switching legs. The circuit stores information that associates multiple different load values with respective configuration settings that each define a number of phases and a number of switching legs. As the load changes, the circuit measures the load and selects an appropriate configuration setting. The circuit applies the selected configuration setting to operate the number of phases and a number of parallel switching legs in the buck converter.

Circuits and methods providing high efficiency over a wide range of load values

In one embodiment, a method for measuring current is described herein. The method comprises shorting first and second inputs of an amplifying circuit to generate a first output signal, and converting the first output signal into an offset cancelation value. The method also comprises passing a current through a power switch, wherein the current generates a voltage drop across the power switch, applying the voltage drop across the first and second inputs of the amplifying circuit to generate a second output signal, and converting the second output signal into a current value. The method further comprises subtracting the offset cancelation value from the current value to generate an offset-compensated current value.

High-current sensing scheme using drain-source voltage

An apparatus and method are disclosed for efficiently using power at a voltage regulator, such as a synchronous buck converter. The synchronous buck converter includes a first switch and a second switch operated by a first control signal and a second control signal, respectively, where the first and second control signals have a corresponding phase difference. A logic circuit measures a duty cycle of an input pulse width modulated (PWM) signal against iterative changes of the phase difference between the first control signal and the second control signal. The logic circuit selects a phase difference corresponding to a minimum value of the PWM signal, thereby optimizing dead time at the synchronous buck converter. The logic circuit may include a Digital Pulse Width Modulator.

Circuits and methods providing dead time adjustment at a synchronous buck converter

Systems and methods for sensing voltage on a chip are described herein. In one embodiment, a voltage sensor comprises a voltage-controlled oscillator coupled to a voltage being sensed, and a plurality of transition detectors, wherein each of the transition detectors is coupled to a different location on the oscillator, and wherein each of the transition detectors is configured to count a number of transitions at the respective location over a time period. The voltage sensor also comprises an adder configured to add the numbers of transitions from the transition detectors to generate an output value that is approximately proportional to the voltage.

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San Diego, CA, United States of America

Chuang Zhang