University of Macau

Seng-Pan U

Rui Paulo Da Silva Martins

Sai-Weng Sin

Yan Zhu

U-Fat Chio

Chi-Hang Chan

Franco Maloberti

Pui-In Mak

He-Gong Wei

Rui P Martins

Yan Lu

Mo Huang

Chi-Seng Lam

Man-Chung Wong

Wai-Hei Choi

Sai-Wang Sin

Li Ding

Yan-Zheng Yang

Rui-Paulo Da Silva Martins

Ning-Yi Dai

Yajie Wu

Chi-Kong Wong

Bidirectional wireless power transfer (WPT) manages to provide a first aid to a mobile device that is running out of energy in urgent circumstances. To facilitate bidirectional WPT with minimum additional cost, a WPT transceiver reconfigurable for performing WPT and wireless power reception (WPR) is provided. The transceiver is reconfigurable between a differential class-D power amplifier (PA) and a full-wave rectifier. A maximum current charging mode (MCCM) is used to maximize a battery-to-battery (B2B) charging efficiency, by directly charging the loading battery with the rectifier, and by powering the PA with the sourcing battery. No output voltage or current regulation is used. Then the number of cascaded charging stages is reduced from five in the conventional design to three.

Reconfigurable bidirectional wireless charging transceiver

A method achieves minimum limit cycle oscillation (LCO) amplitude of a digital low dropout regulator (D-LDO) by adding auxiliary unit power transistors in parallel with the main PMOS array with selected unit strength and LCO mode. An improved D-LDO with reduced LCO amplitude includes an auxiliary power transistor array in selected strength driven by an output of a comparator in parallel with a main power transistor array.

Limit cycle oscillation reduction for digital low dropout regulators

A mixed signal controller for a power quality compensator includes an analog circuit, an analog-to-digital converter (ADC), and a digital circuit. The analog circuit amplifies an input signal from the power quality compensator by a gain factor and outputs an analog signal, which is converted to a digital signal by the ADC. The digital circuit receives the digital signal, calculates the reference compensating current of each phase and then generates a trigger signal via hysteresis PWM to the power quality compensator. The digital circuit includes an evaluation circuit that calculates a value of the system total harmonic distortion after the power quality compensator compensates power and adjusts the gain factor when the value of the system total harmonic distortion reaches a predetermined threshold.

Mixed signal controller

A sampling front-end for analog to digital converter is presented that shares a high speed N-bit ADC at front-end and interleaves the pipelined residue amplification with shared amplifier, which achieves high speed, low power and compact area with high density capacitive DAC structure.

Sampling front-end for analog to digital converter

A comparator is provided and the comparator includes a comparing input unit and a latching unit. Wherein, the comparing input unit has a first input receiving a first comparing signal and has a second input receiving a second comparing signal. The comparing input unit drives a first intermediate node signal at a first intermediate node depending on the first comparing signal according to a first strobe signal, and the comparing input unit drives a second intermediate node signal at a second intermediate node depending on the second comparing signal according to the first strobe signal. The latching unit determines a comparing result according to at least one of the first intermediate node signal and the second intermediate node signal. In addition, the latching unit latches the comparing result according to a second strobe signal.

Comparator and calibration thereof

The present invention provides a pipelined-successive approximation register (SAR) analog-to-digital converter (ADC) circuit with decoupled flip-around MDAC, capacitive attenuation solution and self-embedded offset cancellation. The flip-around MDAC architecture is built for low inter-stage gain implementation. A capacitive attenuation solution is provided for minimizing the power dissipation and optimizing conversion speed. The design reuses SAR ADC to perform offset cancellation, which significantly saves calibration area, power and time.

Analog to digital converter circuit

A novel analog-to-digital converter (ADC) system using a two-step conversion is disclosed. The ADC system is capable of achieving high sampling rate, low power consumption and low complexity. The new proposed ADC is formed by cascading a flash ADC having high sampling rate and low resolution with a successive approximation (SA) ADC having low power consumption and low sampling rate.

Cascade analog-to-digital converting system

A delay generator comprises: a current source for supplying a current; a first delay portion, connected to the current source, comprising at least a plurality of inverters and a first capacitor having a first capacitance; and a second delay portion, connected to the current source, comprising at least a plurality of inverters and a second capacitor having a second capacitance, wherein the first capacitance is the same as the second capacitance, wherein the first delay portion generates a first delay by discharging of the first capacitor, wherein the second delay portion generates a second delay by charging of the second capacitor, and wherein the total delay generated by the delay generator is obtained by summation of the first delay and the second delay.

Delay generator

An analog-to-digital converter (ADC) circuit comprising two time-interleaved successive approximation register (SAR) ADCs. Each of the two time-interleaved SAR ADCs comprises a first stage SAR sub-ADC, a residue amplifier, a second stage SAR sub-ADC and a digital error correction logic. The residue amplifier is shared between the time-interleaved paths, has a reduced gain and operates in sub-threshold to achieve power effective design.

Time-interleaved pipelined-SAR analog to digital converter with low power consumption

The present invention provides an n-bits successive approximation register (SAR) analog-to-digital converting (ADC) circuit, comprising: an n-bits SAR control logic, a p-type capacitor network including a DACarray and a sampling capacitor C, an n-type capacitor network including a DACarray and a sampling capacitor C; and a comparator for comparing outputs from the p-type capacitor network and the n-type capacitor network, wherein a power supply and ground are directly connected to the p-type capacitor network and the n-type capacitor network without using reference voltages produced by a reference voltage generator. The n-bits SAR control logic comprises n shift registers, n bit registers, and a switching logic. The comparator comprises a first pre-amplifier, a second pre-amplifier and a dynamic latch. Alternative, the comparator comprises a four-input pre-amplifier and a dynamic latch.

N-bits successive approximation register analog-to-digital converting circuit

A switched current resistor (SCR) PGA for constant-bandwidth gain control includes an inverting amplifier, a feedback resistor forming a feedback loop between an output side and an input side of the inverting amplifier, and a switched current resistor (SCR) array connected in parallel to the feedback resistor, and configured to tune a gain range between a maximum and a minimum. The SCR array includes a plurality of switched resistors, each comprising a switch in series with a resistor. When the plurality of switched resistors are switched by a gain-control logic, a plurality of switched current sources and a plurality of grounded resistors are switched correspondingly to deliver a transient current, an equivalent of which flows through the plurality of grounded resistors out from the input side of the inverting amplifier, leading to a feedback factor of the PGA being constant.

Switched current resistor programmable gain array for low-voltage wireless LAN and method using the same

A reconfigurable multimode transmitter is disclosed, operating in accordance with a two-step channel selection. The first step provides for a fine channel selection and upconversion of a desired channel to either positive or negative IF. The second step is a coarse channel selection and upconversion of a desired channel to the RF. The receiver and transmitter can be used in a transceiver.

Two-step channel selection for wireless transmitter front-ends

An amplifier circuit includes a transconductance amplifier at an input side of the amplifier circuit, a transimpedance amplifier connected to an output of the transconductance amplifier, and a voltage amplifier connected to an output of the transimpedance amplifier. The transconductance amplifier and the transimpedance amplifier form a low-impedance node at an interface thereof. A feedback circuit is connected between an output of the voltage amplifier and the low-impedance node between the transconductance amplifier and the transimpedance amplifier. The transconductance amplifier, the transimpedance amplifier, and the voltage amplifier form a main amplifier stage. The feedback circuit senses an imbalance in an output of the main amplifier stage, whereby a correction signal is integrated and negatively fed back to the low-impedance node between the transconductance amplifier and the transimpedance amplifier.

DC-offset cancelled programmable gain array for low-voltage wireless LAN system and method using the same

A reconfigurable receiver is disclosed, operating in accordance with a two-step channel selection. The first step provides for a coarse radio frequency (RF) channel selection, to downconvert a desired channel and an image channel of the desired channel to IF. The second step provides for a fine intermediate frequency (IF) channel selection to select either the desired channel or the image channel. The receiver can be used in a transceiver.

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Macau, China

Seng-Pan U