Richtek Technology Corporation

Hsinchu, Taiwan

Richtek Technology Corporation

Hsinchu, Taiwan
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Patent
Richtek Technology Corporation | Date: 2017-08-30

An adaptive charging voltage generator (110) of a mobile device charger (100) includes: a power receiving interface (210) for receiving a DC voltage (VA) and a cable current (IA) from a cable (130); a terminal communication interface (220) for transmitting a charging voltage (VB) and a charging current (IB) to a connection terminal (120) of the mobile device charger (100) and for receiving a communication signal (X1B; X2B) generated by a mobile device (150) from the connection terminal (120); a buck converter (230) for receiving the DC voltage (VA) and the cable current (IA) from the power receiving interface (210) and for generating the charging voltage (VB) and the charging current (IB), wherein the charging voltage (VB) is lower than the DC voltage (VA) while the charging current (IB) is greater than the cable current (IA); and a charging voltage control circuit (260) coupled with the buck converter (230) and configured for controlling the buck converter (230) according to the communication signal (X1B; X2B).


Patent
Richtek Technology Corporation | Date: 2017-01-25

An AC-to-DC power converter includes a rectifier for generating a rectified voltage based on an AC voltage; an input capacitor coupled between the rectifier and a fixed-voltage terminal; a first inductive element; a first auxiliary capacitor; a first switch coupled between the input capacitor and the first inductive element; a second switch coupled between the first inductive element and the fixed-voltage terminal; a circuitry node; an auxiliary switch for coupling between the circuitry node and the first auxiliary capacitor or between the first auxiliary capacitor and the fixed-voltage terminal; a first diode; a second diode; a control signal generating circuit for controlling the first switch and the second switch; and an auxiliary switch control circuit for controlling the auxiliary switch.


A lateral double diffused metal oxide semiconductor device, includes: a P-type substrate, an epitaxial layer, a P-type high voltage well, a P-type body region, an N-type well, an isolation oxide region, a drift oxide region, a gate, an N-type contact region, a P-type contact region, a top source, a bottom source, and an N-type drain. The P-type body region is between and connects the P-type high voltage well and the surface of the epitaxial layer. The P-type body region includes a peak concentration region, which is beneath and indirect contact the surface of the epitaxial layer, wherein the peak concentration region has a highest P-type impurity concentration in the P-type body region. The P-type impurity concentration of the P-type body region is higher than a predetermined threshold to suppress a parasitic bipolar transistor such that it does not turn ON.


A MEMS device includes: a fixed structure, a movable structure, and a compensation circuit. The fixed structure includes a fixed electrode and a fixed compensation electrode. The movable structure includes a movable electrode and a movable compensation electrode. The movable electrode and the fixed electrode form a sensing capacitor, and the movable compensation electrode and the fixed compensation electrode form a compensation capacitor. The compensation circuit compensates a sensing signal generated by the sensing capacitor with a compensation signal generated by the compensation capacitor. The sensing capacitor and the compensation capacitor do not form a differential capacitor pair. A proportion of the sensing area of the compensation capacitor to the sensing area of the sensing capacitor is lower than 1.


Patent
Richtek Technology Corporation | Date: 2017-03-09

A control chip of a driving circuit for driving a LED array shares a ground terminal with the LED array so that, without an additional winding, the driving circuit can provide a supply voltage for the control chip, implement a zero-current switching function, and implement an over-voltage protection function. Since no additional windings are needed, the related costs and the size of the driving circuit are decreased.


The present invention discloses a resonant wireless power transmitter circuit, which has an input impedance. The resonant wireless power transmitter circuit includes: a driver circuit coupled with a power supply, which includes at least a power switch; a switching resonant control circuit coupled with the driver circuit, such that the driver operates at a pre-determined or a variable resonant frequency; an adjustable impedance matching circuit coupled with the driver circuit, which includes at least a varactor; a transmitter circuit coupled with the impedance matching circuit and the driver circuit, which includes at least a transmitter coil; and an impedance control circuit coupled with the adjustable impedance matching circuit and the driver circuit, which provides an impedance control signal to control the reactance of the varactor, such that the input impedance of the resonant wireless power transmitter circuit is matched at the pre-determined or the variable resonant frequency.


Patent
Richtek Technology Corporation | Date: 2016-12-22

A control circuit includes: a comparing circuit, having a first input terminal and second input terminal, configured to operably generate a comparison signal according signals received by the first and second input terminals, wherein the first input terminal is utilized for coupling with a reference signal and the second input terminal is utilized for coupling with a feedback signal; a periodic signal generating circuit configured to operably generate a periodic signal and apply the periodic signal to the first input terminal or the second input terminal of the comparing circuit; and a control signal generating circuit for controlling an on time of a power switch according to the comparison signal. The periodic signal generating circuit clamps a limit of the periodic signal to a predetermined value, but does not configure the slope of the periodic signal to be zero when there is no current passing through the inductor.


Patent
Richtek Technology Corporation | Date: 2016-06-24

A high-side device includes: a substrate, an epitaxial layer, a high voltage well, a body region, a gate, a source, a drain, and a buried region. A channel junction is formed between the body region and the high voltage well. The buried region is formed in the substrate and the epitaxial layer, and in a vertical direction, a part of the buried region is located in the substrate and another part of the buried region is located in the epitaxial layer. In the channel direction, an inner side boundary of the buried region is between the drain and the channel junction. An impurity concentration of a second conductive type of the buried region is sufficient to prevent the high voltage well between the channel junction and the drain from being completely depleted when the high-side power device operates in a conductive operation. A corresponding manufacturing method is also disclosed.


The present invention provides a flyback power converter with a programmable output and a control circuit and a control method thereof. The flyback power converter converts an input voltage to a programmable output voltage according to a setting signal, wherein the programmable output voltage switches between different levels. The flyback power converter includes: a transformer circuit, a power switch circuit, a current sense circuit, an opto-coupler circuit, and a control circuit. The control circuit adaptively adjusts an operation signal according to a level of the programmable output voltage, to maintain a same or relatively higher operation frequency of the operation signal when the programmable output voltage switches to a relatively lower level, so as to maintain a phase margin while supplying the same output current.


Patent
Richtek Technology Corporation | Date: 2016-06-01

A power converter includes: a transformer having a primary side winding to receive a rectified voltage, and a secondary side winding to generate an output DC voltage; a gallium nitride (GaN) M0SFET, coupled to the primary side winding for controlling a primary side current flowing through the primary side winding; a sensing resistor coupled to the GaN transistor switch, for sensing the primary side current to generate a current sensing signal; and a switch control unit, for controlling the GaN transistor switch according to the current sensing signal. The sensing resistor and the GaN transistor switch are connected at a ground node having a voltage level which is the ground of the primary side.

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