Dialog Semiconductor Gmbh

Iwatt Inc.

Diaglo Semiconductor Inc.

Hien Huu Bui

Pengju Kong

Fuqiang Shi

Yong Li

John William Kesterson

Duc Doan

Junjie Zheng

David H Nguyen

Hanguang Zhang

Jianming Yao

Tao Li

Andrew Kwok-Cheung Lee

Wenbo Liang

Judy Sha

Liang Yan

Xiaolin Gao

Cong Zheng

Wenduo Liu

Jun Zheng

Allan Ming-Lun Lin

Carrie Seim

Xiaoyan Wang

Clarita C Poon

Chuanyang Wang

Mengfei Liu

Jiandong Zhang

Xiaye Wang

John Shi

Kuangzhe Xu

Vijay Kanagala

Huangxuan Gong

A gate drive control circuit is provided that charges a gate voltage of a power switch transistor during a power switch transistor on-time period. During a first portion of the on-time period, the gate drive control circuit charges the gate voltage through a relatively-low resistance. During a second portion of the on-time period, the gate drive control circuit charges the gate voltage through a relatively-high resistance. Finally, during a third portion of the on-time period, the gate drive control circuit charges the gate voltage through another relatively-low resistance.

Adaptive gate drive for a power switch transistor in a switching power converter

Disclosed is a system for determining a primary switching event in an isolated converter having a primary-side and a secondary-side. The system includes a primary-switch (PS) on the primary-side, a synchronous rectifier (SR) on the secondary-side, an integration circuit, and a SR controller. The integration circuit is in signal communication with the SR on the secondary-side and the SR controller is in signal communication with the SR and the integration circuit. The SR is configured to produce a drain-to-source voltage (V) and the integration circuit is configured to integrate a difference between the Vand a output voltage (V) (produced by the secondary-side) over time to produce a Vover time value (V). The SR controller is configured to determine if the Vis greater than a first threshold voltage (V) and determine the primary switching event when the Vis greater than a second threshold voltage (VS).

System and method for determining a primary switching event in an isolated converter

Disclosed is a universal primary-only output current regulation for a flyback converter. A controller determines a peak sense resistor voltage responsive to a desired average output current for the flyback converter during a continuous conduction mode of operation. After a power switch transistor is cycled on, the controller monitors a sense resistor voltage to determine when the sense resistor voltage equals the peak sense resistor voltage. The controller switches off the power switch transistor when the sense resistor voltage equals the peak sense resistor voltage to maintain an average output current for the flyback converter equal to the desired average output current.

Universal output current regulation for a flyback converter

A synchronous rectifier controller method is provided for controlling the on and off periods of a synchronous rectifier (SR) switch transistor in a switching power converter. The method includes a first step of monitoring an unfiltered to control whether the SR switch transistor is turned on during a first part of a power switch cycle. The method also includes a second step of monitoring a filtered SR switch signal to control whether the SR switch is turned on during a remaining second part of the power switch cycle.

Adaptive synchronous rectifier sensing deglitch

A synchronous rectifier controller for controlling the on and off periods of a synchronous rectifier switch transistor in a switching power converter. In particular, the synchronous rectifier controller is configured to adaptively enable and disable a deglitch filter for filtering a turn-on signal for the synchronous rectifier switch transistor. In this fashion, the synchronous rectifier switch transistor may be switched on more rapidly during periods when the deglitch filter is disabled for greater efficiency yet the switching power converter is protected by the deglitch filter when it is not disabled.

An adaptive valley mode switching power converter is provided that switches on a power switch within valley periods of a resonant voltage oscillation for the power switch. Each valley period is determined with regard to a valley threshold voltage.

Adaptive valley mode switching

A switching power converter may include a power switch coupled to a primary winding of a transformer, and a primary controller configured to turn on and off the power switch, a synchronous rectifier switch coupled to a secondary winding of a transformer, and a synchronous rectifier controller configured to turn on and off the synchronous rectifier switch. The synchronous rectifier controller may monitor a voltage across the synchronous rectifier switch. The synchronous rectifier controller may determine a period of a resonant oscillation of the voltage across the synchronous rectifier switch following at least one cycling off of the synchronous rectifier switch. The synchronous rectifier controller may adjust the minimum off-time period for the synchronous rectifier switch based on the period of the resonant oscillation. The synchronous rectifier controller may adaptively adjust a minimum off-time period for the synchronous rectifier switch.

Synchronous rectifier control with adaptive minimum off-time

A switching power converter is provided that includes a detector to detect whether a controller power supply voltage has fallen below a threshold voltage during a dormant period in which a power switch is no longer cycling to deliver power to a load. In response to a detection of such a threshold crossing by the detector, a controller powered by the controller power supply voltage is configured to cycle the power switch to replenish the controller power supply voltage.

Regulation of the power supply voltage for a flyback converter controller

A power supply control system delivers regulated power to a load via a delivery cable. The power supply control system includes a power stage operable to deliver power to the load at a first regulated voltage level and a second regulated voltage level. A cable offset voltage unit generates an offset voltage signal representing a drop in voltage across the delivery cable. The offset voltage signal is generated based on a first cable drop compensation value when the power stage is operated to deliver power at the first regulated voltage level and based on a second cable drop compensation value when the power stage is operated to deliver power at the second regulated voltage level. A controller coupled to the power stage and the cable offset voltage unit controls the power stage to deliver the regulated power to the load based at least in part on the offset voltage signal.

Adaptive cable drop compensation based on scalable cable offset factor

A method for estimating an output voltage of a power converter comprises sensing a voltage waveform representative of the output voltage; and detecting a first gap and a second gap. The first gap is between a time when the sensed voltage waveform crosses a first voltage reference and a time when the sensed voltage waveform crosses a second voltage reference at a voltage offset below the first voltage reference. The second gap is between a time when the sensed voltage waveform crosses a third voltage reference and a time when the sensed voltage waveform crosses the second voltage reference, the third voltage referenced at a predetermined voltage above the second voltage reference. Responsive to the first gap exceeding a threshold, a tracking error is computed based on the first gap; and responsive to the first gap not exceeding the threshold, the tracking error is computed based on the second gap.

Primary sensing of output voltage for an AC-DC power converter

A power converter system comprises a switching power converter having a primary side and a secondary side that are electrically isolated from each other. A first controller on the primary side of the switching power converter controls a switch in the switching power converter on or off at a switching frequency of the switching power converter to regulate an output voltage of the switching power converter. A second controller on the secondary side of the switching power converter encodes information into one or more pulses such that a first duration between the consecutive pulses corresponds to a first logic level and a second duration between the consecutive pulses corresponds to a second logic level, the second duration being greater than the first duration.

Protocol for communication between secondary side and primary side of isolated switching power converters

A flyback converter is provided that includes a base driver for driving a base current into a base of a BJT power switch. The base driver is controlled so as to adaptively vary the base current across at least some of the pulses.

Adaptive BJT driver for switching power converter

A power converter includes a transformer with a primary and a secondary winding and a switch. A controller of the power converter at the primary winding side of the transformer generates a control signal to turn on or turn off the switch, the switch being turned on responsive to the control signal being in a first state and the switch being turned off responsive to the control signal being in a second state. The controller determines current through the primary winding generated while the switch is turned on and indirectly detects an input voltage to the power converter based on the current through the primary winding generated while the switch is turned on. The controller in turn may detect conditions such as a loss of power or brown out at the input of the power converter based on the indirectly detected input voltage.

AC-DC power supply input voltage detection and monitoring

A switching power converter provides regulated output power to a load. The switching power converter comprises a transformer including a primary winding coupled to an input voltage, a secondary winding coupled to an output of the switching power converter, an auxiliary winding on a primary side of the transformer, and a switch coupled to the primary winding of the transformer. Output voltage across the secondary winding is reflected as a feedback voltage across the auxiliary winding. The switching power converter detects output current based on a reset time of the transformer. Based on the detected output power, the switching power converter controls switching of the switch to provide regulated output power.

Growing community of inventors

San Jose, CA, United States of America

Hien Huu Bui