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Hangzhou, China

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Cheng K.-Y.,Texas Instruments | Tian S.,Virginia Polytechnic Institute and State University | Yu F.,Silergy Corporation | Lee F.C.,Virginia Polytechnic Institute and State University | And 2 more authors.
IEEE Transactions on Power Electronics | Year: 2014

This paper presents a digital hybrid ripple-based constant on-time control scheme for voltage regulator modules (VRMs). Due to the sampling effects of the digital implementation, the stability issue becomes worse than the analog ripple-based control schemes, especially when the composite output capacitors are utilized. In order to stabilize the system and to fulfill the output impedance requirement of adaptive voltage positioning (AVP), a hybrid ramp compensation strategy, which includes the external ramp and the estimated current ramp, is proposed in this paper. No complicated compensators are required as the conventional voltage-mode control. The small-signal model of the proposed architecture is derived to provide the design guideline for the ramp compensation gains with different output capacitors. Besides, the oversampling effect of the output voltage by using analog-to-digital converters (ADCs) are also analyzed by using the presented model. Simulation and experimental results show that the proposed digital ripple-based control architecture can achieve fast load transient performance and to fulfill the AVP design requirements of single-phase VRMs. © 2013 IEEE.


Cheng K.-Y.,Texas Instruments | Cheng K.-Y.,Virginia Polytechnic Institute and State University | Yu F.,Silergy Corporation | Lee F.C.,Virginia Polytechnic Institute and State University | Mattavelli P.,Virginia Polytechnic Institute and State University
IEEE Transactions on Power Electronics | Year: 2013

This paper proposes a new digital enhanced V 2 -type constant on-time control architecture for solving the ripple oscillation issues when using low-equivalent series resistance (ESR) capacitors in a buck converter. Instead of directly sensing the inductor current, an inductor current ramp estimator with the drift compensation is presented as adding a virtual ESR ripple to the output voltage. Only the input and output voltages are required to be sampled with analog-to-digital converters (ADCs) for estimating the inductor current ramp. Since the sampling rate and resolution requirements of ADCs for voltage sensing are usually less critical with compared to direct current sensing, the proposed digital control architecture is practical for low-cost applications. Besides, the limit-cycle oscillations due to the sampling effects can also be improved by using the estimated current ramp. Furthermore, the small-signal model of the proposed digital enhanced V 2 control architecture is provided to design the estimated current ramp amplitude to stabilize the system and to optimize the system performance. The drift compensation effect is also analyzed in this paper. The effectiveness of the proposed control architecture with the current ramp estimator has been verified with simulation and experimental results by using an FPGA-based hardware platform. © 2012 IEEE.


Zhao C.,Silergy Corporation | Chen M.,Zhejiang University | Zhang G.,Zhejiang University | Wu X.,Zhejiang University | Qian Z.,Zhejiang University
IEEE Transactions on Power Electronics | Year: 2010

The dc-dc topologies with capacitive output filter are going to be widely used especially for high-output current applications because of its inherent advantages in the lower voltage stress on rectifiers and the smaller occupied printed circuit board layout area at the secondary side. However, the parasitic resonance between the equivalent leakage inductance of the power transformer and the equivalent output junction capacitance of the rectifier still practically exists in the center-tapped rectification configuration, which leads to considerable voltage ringing on the rectifier and then results in the utilization of the rectifier with much higher breakdown voltage rate and the decrease of conversion efficiency. Moreover, the relatively larger output-current ripple induces the both larger conduction loss in the secondary-side windings of the power transformer and the capacitive output filter. In this paper, a novel symmetrical rectifier configuration is proposed, which can effectively clamp the practical voltage stress on the rectifier without any parasitical voltage spike and reduce the output-current ripple due to the bypass effect of the auxiliary flying-balancing capacitors. The leakage inductance and the output filter capacitor can be treated as an inherent small LC filter to reduce the output voltage ripple further. Based on the theoretical analysis and the optimal design considerations, a 300-W lab-made LLC resonant dc-dc converter with this proposed configuration is built up to verify its advantages in high conversion efficiency. © 2011 IEEE.


Zhao C.,Hangzhou Dianzi University | Zhao C.,Silergy Corporation | Xie X.,Hangzhou Dianzi University | Dong H.,Hangzhou Dianzi University | Liu S.,Hangzhou Dianzi University
IEEE Transactions on Power Electronics | Year: 2014

Based on the concept derivation, this paper proposes an improved synchronous rectifier (SR) driving strategy focusing on the quasi-resonant primary-side regulation (QR-PSR) Flyback converter, for the applications of dc-dc front-end converter and ac-dc PFC converter both, to prevent reverse energy flowing in light-load/standby mode. Three different implementation candidates are exhibited and analyzed. This proposed driving strategy is programmable for the practical design with input voltage feedforward effect and helpful for achieving the rigorous target of low power loss under light output load condition presented by the U.S. Department of Energy (DoE). Two 60 W (12 V/5 A) lab-made prototypes of synchronous rectified QR-PSR Flyback ac-dc PFC converter and dc-dc front-end converter are built up, respectively, to verify the feasibility of this proposed driving strategy. In the lab-made prototype of ac-dc PFC converter, it improves the overall conversion efficiency more than 3% in light-load mode; in the lab-made prototype of dc-dc front-end converter, it saves the light load power loss up to 0.5 W, especially with 110 Vac input. Reliable operation is achieved when the proposed SR driving strategy is practically designed with enough margin; however, too large design margin could decrease the average conversion efficiency. © 2014 IEEE.


Trademark
Silergy Corporation | Date: 2016-10-21

Chargers for electric batteries; Surveying machines and instruments; Power supplies, electrical; Rechargeable electric batteries; Chargers for electronic cigarettes; Electric light dimmers; Voltage surge protectors; Current transformers; Electric voltage transformers; Electric sensors; Voltage regulators; Voltage stabilizing power supply; Semi-conductors; Transistors; Light emitting diodes (LEDs); Printed circuits; Integrated circuits; Silicon chips; Semiconductor chips; Computer chips; Printed circuit boards; POWER METERS; Galvanometers; Dynamometers; oscilloscope; Capacitators; Pressure measuring apparatus; Pressure indicators; Flowmeters; Voltage regulators for vehicles; Automatic indicators of low pressure in vehicle tires; Audio- and video-receivers; Sound transmitting apparatus; Loudspeakers; Walkie-talkies; Transponders; Modems; Computer peripheral devices; Computer operating programs, recorded?; Recorded computer game programs; Wearable activity trackers; Smartphones; ELECTRONIC CONTROLLERS FOR ELECTRICITY METERS; Amplifiers; Electronic and optical communications instruments and components, namely, optical data links; Electronic and optical communications instruments and components, namely, optical receivers; Electronic and optical communications instruments and components, namely, optical transceivers; Electronic and optical communications instruments and components, namely, optical transmitters; Computers; Data processing apparatus; Current rectifiers; Smart card readers; Transceivers; Ethernet transceivers; Electronic switchers for audio and video signals; Network communication equipment.


There is disclosed a driver for driving a series arrangement being a variable number of strings of LEDs wherein each string has a capacitance connected in parallel with the respective string; the driver comprising: a controllable current source adapted to be connected in series between the series arrangement and a rectified AC supply to and source a controllable current (Istr) through the series arrangement; and a current source controller adapted to control the controllable current source; wherein the current source controller is operable to source a relatively lower current (I_(LED)) when a difference (Vstr3A) between the voltage across the series arrangement and the voltage of the rectified AC supply is relatively higher and a relatively higher current (I_(LED)) when the difference is relatively lower. Associated driver circuits and lighting circuits, and methods are also disclosed.


Patent
Silergy Corporation | Date: 2016-12-21

A differential coupling path is provided for power measurement communication between a host device and a line side device. The line side device couples to AC power grid to extract voltage signals and current signals using various voltage and current sensors. The extracted voltage signal and current signal are converted to digital signals by internal A/D converters within the line device and then sent to the host device through the differential coupling path coupled between the host device and the line side device. The host device may couple to one or more line side devices via multiple differential coupling paths.


Trademark
SILERGY Corporation | Date: 2016-06-03

Audio amplifiers; Audio circuit boards; Battery charge devices; Battery chargers; Battery monitors; Battery power supplies for medical ventilators; Chargers for batteries; LED and HID light controls; Light systems comprising light sensors and switches; Power controllers; Power supplies; Pressure sensors; Semiconductor chip sets; Semiconductor chips; Semiconductor devices; Semiconductor lead frames; Semiconductor power elements; Semiconductor wafers; Surge protectors; Battery chargers; Battery power supplies for medical ventilators; Cell phone battery chargers; Chargers for batteries; Consumer electronic products, namely, audio amplifiers, audio speakers, audio receivers, electrical audio and speaker cables and connectors, audio decoders, video decoders, speakers, power conversion devices, power converters, and power inverters; DC/AC power converters; Electric meters; Electric power converters; Electrical surge arresters; Electronic controllers for use with power converters; Electronic power supplies for driving electric motors; Electronic controllers for use with power converters; High-frequency switching power supplies; Inverters for power supply; Lighting controls; Monitoring devices for monitoring battery performance characteristics; Power controllers; Rechargeable electric batteries; Transient voltage surge suppressors with power conditioning technology; Uninterruptible electrical power supplies; Very large scale integration (VLSI) semiconductor integrated circuits; Voltage regulators; Voltage regulators for electric power; Voltage surge protectors; Voltage stabilizing power supply.


Patent
Silergy Corporation | Date: 2016-01-25

A differential coupling path is provided for power measurement communication between a host device and a line side device. The line side device couples to AC power grid to extract voltage signals and current signals using various voltage and current sensors. The extracted voltage signal and current signal are converted to digital signals by internal A/D converters within the line device and then sent to the host device through the differential coupling path coupled between the host device and the line side device. The host device may couple to one or more line side devices via multiple differential coupling paths.


Trademark
Silergy Corporation | Date: 2016-03-31

Electrostatic discharge protectors; Transient voltage suppressors; Electromagnetic interference filters; Voltage surge protectors; Power supplies, electrical; Integrated circuits.

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