Patents Assigned to Richtek Technology Corporation, R.O.C.
  • Patent number: 9287796
    Abstract: The present invention discloses an isolated power converter circuit and a control method thereof. The isolated power converter circuit includes: a transformer circuit, a power switch circuit, an opto-coupler circuit, and a control circuit. The transformer circuit includes a first winding and a second winding. The power switch circuit is coupled to the transformer circuit to control it according to a driving signal. The opto-coupler circuit generates a feedback signal. The control circuit is coupled to the power switch circuit and the opto-coupler circuit, for generating the driving signal according to the feedback signal. The control circuit includes a distinguishing circuit for distinguishing a status of the feedback signal.
    Type: Grant
    Filed: February 12, 2013
    Date of Patent: March 15, 2016
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventors: Chia-Wei Liao, Jing-Meng Liu
  • Patent number: 9105757
    Abstract: The present invention discloses a junction barrier Schottky (JBS) diode and a manufacturing method thereof. The JBS diode includes: an N-type gallium nitride (GaN) substrate; an aluminum gallium nitride (AlGaN) barrier layer, which is formed on the N-type GaN substrate; a P-type gallium nitride (GaN) layer, which is formed on or above the N-type GaN substrate; an anode conductive layer, which is formed at least partially on the AlGaN barrier layer, wherein a Schottky contact is formed between part of the anode conductive layer and the AlGaN barrier layer; and a cathode conductive layer, which is formed on the N-type GaN substrate, wherein an ohmic contact is formed between the cathode conductive layer and the N-type GaN substrate, and the cathode conductive layer is not directly connected to the anode conductive layer.
    Type: Grant
    Filed: September 28, 2013
    Date of Patent: August 11, 2015
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventors: Chih-Fang Huang, Tsung-Yi Huang, Chien-Wei Chiu, Tsung-Yu Yang, Ting-Fu Chang, Tsung-Chieh Hsiao, Ya-Hsien Liu, Po-Chin Peng
  • Patent number: 9018070
    Abstract: The present invention discloses a transient voltage suppressor (TVS) circuit, and a diode device therefor and a manufacturing method thereof. The TVS circuit is for coupling to a protected circuit to limit amplitude of a transient voltage which is inputted to the protected circuit. The TVS circuit includes a suppressor device and at least a diode device. The diode device is formed in a substrate, which includes: a well formed in the substrate; a separation region formed beneath the upper surface; a anode region and a cathode region, which are formed at two sides of the separation region beneath the upper surface respectively, wherein the anode region and the cathode region are separated by the separation region; and a buried layer, which is formed in the substrate below the well with a higher impurity density and a same conductive type as the well.
    Type: Grant
    Filed: September 10, 2014
    Date of Patent: April 28, 2015
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventors: Tsung-Yi Huang, Jin-Lian Su
  • Patent number: 9018703
    Abstract: The present invention discloses a hybrid high voltage device and a manufacturing method thereof. The hybrid high voltage device is formed in a first conductive type substrate, and includes at least one lateral double diffused metal oxide semiconductor (LDMOS) device region and at least one vent device region, wherein the LDMOS device region and the vent device region are connected in a width direction and arranged in an alternating order. Besides, corresponding high voltage wells, sources, drains, body regions, and gates of the LDMOS device region and the vent device region are connected to each other respectively.
    Type: Grant
    Filed: February 10, 2014
    Date of Patent: April 28, 2015
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventors: Tsung-Yi Huang, Chien-Hao Huang
  • Patent number: 9012989
    Abstract: The present invention discloses a high voltage device and a manufacturing method thereof. The high voltage device is formed in a first conductive type substrate, wherein the substrate includes isolation regions defining a device region. The high voltage device includes: a drift region, located in the device region, doped with second conductive type impurities; a gate in the device region and on the surface of the substrate; and a second conductive type source and drain in the device region, at different sides of the gate respectively. From top view, the concentration of the second conductive type impurities of the drift region is distributed substantially periodically along horizontal and vertical directions.
    Type: Grant
    Filed: September 11, 2014
    Date of Patent: April 21, 2015
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventors: Tsung-Yi Huang, Chien-Hao Huang
  • Patent number: 8981429
    Abstract: The present invention discloses a high electron mobility transistor (HEMT) and a manufacturing method thereof. The HEMT device includes: a substrate, a first gallium nitride (GaN) layer; a P-type GaN layer, a second GaN layer, a barrier layer, a gate, a source, and a drain. The first GaN layer is formed on the substrate, and has a stepped contour from a cross-section view. The P-type GaN layer is formed on an upper step surface of the stepped contour, and has a vertical sidewall. The second GaN layer is formed on the P-type GaN layer. The barrier layer is formed on the second GaN layer. two dimensional electron gas regions are formed at junctions between the barrier layer and the first and second GaN layers. The gate is formed on an outer side of the vertical sidewall.
    Type: Grant
    Filed: May 20, 2013
    Date of Patent: March 17, 2015
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventors: Chih-Fang Huang, Po-Chin Peng, Tsung-Chieh Hsiao, Ya-Hsien Liu, K. C. Chang, Hung-Der Su, Chien-Wei Chiu, Tsung-Yi Huang, Tsung-Yu Yang, Ting-Fu Chang
  • Patent number: 8963237
    Abstract: The present invention discloses a high voltage device and a manufacturing method thereof. The high voltage device includes: a substrate, having an isolation structure for defining a device region; a drift region located in the device region, wherein from top view, the drift region includes multiple sub-regions separated from one another but are electrically connected with one another; a source and a drain in the device region; and a gate on the surface of the substrate and between the source and drain in the device region.
    Type: Grant
    Filed: September 17, 2011
    Date of Patent: February 24, 2015
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventors: Tsung-Yi Huang, Chien-Hao Huang
  • Patent number: 8941325
    Abstract: The present invention discloses a current splitter circuit for splitting a supply current to multiple light emitting device strings of a light emitting device array. The current splitter circuit includes: a minimum selector circuit coupled to the multiple light emitting device strings to generate a minimum signal which indicates a minimum voltage of the light emitting device strings; and multiple current source circuits each including a first current source end coupled to a corresponding light emitting device string, a second current source end coupled to ground, and a current source control end receiving a current control signal related to the minimum signal, so as to control currents through the corresponding light emitting device string.
    Type: Grant
    Filed: September 6, 2011
    Date of Patent: January 27, 2015
    Assignee: Richtek Technologies Corporation, R.O.C.
    Inventors: Jing-Meng Liu, Chiawei Liao
  • Patent number: 8928078
    Abstract: The present invention discloses a double diffused metal oxide semiconductor (DMOS) device and a manufacturing method thereof. The DMOS device includes: a first conductive type substrate, a second conductive type high voltage well, a gate, a first conductive type body region, a second conductive type source, a second conductive type drain, a first conductive type body electrode, and a first conductive type floating region. The floating region is formed in the body region, which is electrically floating and is electrically isolated from the source and the gate, such that the electrostatic discharge (ESD) effect is mitigated.
    Type: Grant
    Filed: December 25, 2012
    Date of Patent: January 6, 2015
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventors: Tzu-Cheng Kao, Jian-Hsing Lee, Jin-Lian Su, Huan-Ping Chu, Hung-Der Su
  • Patent number: 8890485
    Abstract: A charger circuit comprising: a charging path coupled between an input voltage and a battery; a power switch on the charging path; a switch control circuit controlling the power switch; a timer counting a charging period; and a low current control circuit issuing a signal to the switch control circuit to control the power switch such that a charging current is maintained to be a predetermined low current when the timer counts to a predetermined maximum charging period.
    Type: Grant
    Filed: October 6, 2009
    Date of Patent: November 18, 2014
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventors: Nien-Hui Kung, Kwan-Jen Chu
  • Patent number: 8878304
    Abstract: The present invention discloses a fuse circuit for final test trimming of an integrated circuit (IC) chip. The fuse circuit includes at least one electrical fuse, at least one control switch corresponding to the electrical fuse, and a resistant device. The electrical fuse is connected with the control switch in series between a predetermined pin and a grounding pin. The control switch receives a control signal to determine whether a predetermined current flows through the corresponding electrical fuse and breaks the electrical fuse. The resistant device is coupled between a bulk terminal and a source terminal to increase a resistance of a parasitic channel, such that an electrostatic discharge (ESD) protection is enhanced, and errors of final test trimming of an IC chip are avoided.
    Type: Grant
    Filed: January 25, 2012
    Date of Patent: November 4, 2014
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventors: Li-Wen Fang, Chih-Hao Yang, An-Tung Chen
  • Patent number: 8859375
    Abstract: The present invention discloses a high voltage device and a manufacturing method thereof. The high voltage device is formed in a first conductive type substrate, wherein the substrate includes isolation regions defining a device region. The high voltage device includes: a drift region, located in the device region, doped with second conductive type impurities; a gate in the device region and on the surface of the substrate; and a second conductive type source and drain in the device region, at different sides of the gate respectively. From top view, the concentration of the second conductive type impurities of the drift region is distributed substantially periodically along horizontal and vertical directions.
    Type: Grant
    Filed: October 17, 2011
    Date of Patent: October 14, 2014
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventors: Tsung-Yi Huang, Chien-Hao Huang
  • Patent number: 8859373
    Abstract: The present invention discloses a high voltage device and a manufacturing method thereof. The high voltage device is formed in a substrate. The high voltage device includes: a gate, a source and drain, a drift region, and a mitigation region. The gate is formed on an upper surface of the substrate. The source and drain are located at both sides of the gate below the upper surface respectively, and the source and drain are separated by the gate. The drift region is located at least between the gate and the drain. The mitigation region is formed below the drift region, and the drift region has an edge closer to the source. A vertical distance between this edge of the drift region and the mitigation region is less than or equal to five times of a depth of the drift region.
    Type: Grant
    Filed: October 17, 2013
    Date of Patent: October 14, 2014
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventors: Tsung-Yi Huang, Chien-Wei Chiu
  • Patent number: 8860082
    Abstract: The present invention discloses a transient voltage suppressor (TVS) circuit, and a diode device therefor and a manufacturing method thereof. The TVS circuit is for coupling to a protected circuit to limit amplitude of a transient voltage which is inputted to the protected circuit. The TVS circuit includes a suppressor device and at least a diode device. The diode device is formed in a substrate, which includes: a well formed in the substrate; a separation region formed beneath the upper surface; a anode region and a cathode region, which are formed at two sides of the separation region beneath the upper surface respectively, wherein the anode region and the cathode region are separated by the separation region; and a buried layer, which is formed in the substrate below the well with a higher impurity density and a same conductive type as the well.
    Type: Grant
    Filed: July 15, 2012
    Date of Patent: October 14, 2014
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventors: Tsung-Yi Huang, Jin-Lian Su
  • Patent number: 8853994
    Abstract: The present invention discloses an analog photovoltaic power circuit, including: a photovoltaic device group for receiving photo energy to generate an input voltage, the input voltage corresponding to an input current; a power stage circuit for receiving the input voltage and generating an output voltage; an optimum current or voltage estimation circuit for receiving a predetermined voltage and estimating an optimum current or voltage point corresponding to an optimal output point according to a direction of variation of the input current and a direction of variation of the power generated by the photovoltaic device group; and an analog comparison and control circuit for comparing the optimum current or voltage with the input current or voltage, to thereby control the operation of the power stage circuit.
    Type: Grant
    Filed: December 1, 2011
    Date of Patent: October 7, 2014
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventor: Jing-Meng Liu
  • Patent number: 8853960
    Abstract: The present invention discloses a dimming control circuit and a method for generating analog and digital signals according to an analog control signal. The dimming control circuit according to the present invention comprises an input for receiving an analog control signal; a digital dimming circuit for receiving the analog control signal and generating a digital signal; an analog dimming circuit for receiving the analog control signal and generating an analog signal; and a power circuit enabled by the digital signal for converting a supply voltage to an output voltage according to the analog signal generated by the analog dimming circuit.
    Type: Grant
    Filed: October 8, 2008
    Date of Patent: October 7, 2014
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventors: Chiawei Liao, Hsin-Kai Chiang
  • Patent number: 8841723
    Abstract: The present invention discloses an LDMOS device having an increased punch-through voltage and a method for making same. The LDMOS device includes: a substrate; a well of a first conductive type formed in the substrate; an isolation region formed in the substrate; a body region of a second conductive type in the well; a source in the body region; a drain in the well; a gate structure on the substrate; and a first conductive type dopant region beneath the body region, for increasing a punch-through voltage.
    Type: Grant
    Filed: March 10, 2010
    Date of Patent: September 23, 2014
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventors: Tsung-Yi Huang, Huan-Ping Chu, Ching-Yao Yang, Hung-Der Su
  • Patent number: 8836294
    Abstract: The present invention discloses a switching regulator, a control circuit and a control method therefor. The switching regulator comprises an upper gate switch, a lower gate switch, and an inductor connected to a switching node. When a current passing through the upper gate switch or the inductor is lower than a threshold, the lower gate switch is kept OFF until a next cycle, and during the cycle wherein the lower gate switch is OFF, the upper gate switch is turned ON for a period of time.
    Type: Grant
    Filed: June 16, 2011
    Date of Patent: September 16, 2014
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventor: Nien-Hui Kung
  • Patent number: 8835258
    Abstract: The present invention discloses a high voltage device and a manufacturing method thereof. The high voltage device is formed in a first conductive type substrate, wherein the substrate has an upper surface. The high voltage device includes: a second conductive type buried layer, which is formed in the substrate; a first conductive type well, which is formed between the upper surface and the buried layer; and a second conductive type well, which is connected to the first conductive type well and located at different horizontal positions. The second conductive type well includes a well lower surface, which has a first part and a second part, wherein the first part is directly above the buried layer and electrically coupled to the buried layer; and the second part is not located above the buried layer and forms a PN junction with the substrate.
    Type: Grant
    Filed: March 16, 2013
    Date of Patent: September 16, 2014
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventors: Tsung-Yi Huang, Huan-Ping Chu
  • Patent number: 8780587
    Abstract: A control circuit of a switching regulator, which controls rectified power within a predetermined range, detects an input voltage and an input current to generate a voltage detection signal and a current detection signal respectively, and the voltage detection signal and the current detection signal are multiplied by one the other to generate a power index. The control circuit generates an error signal according to the power index and a reference signal. A low-pass-filter filters a high frequency band in the process. A control signal generation circuit of the control circuit generates a control signal according to the error signal. And a driver circuit of the control circuit generates an operation signal according to the control signal, for switching a power switch to convert the rectified power to an output voltage.
    Type: Grant
    Filed: November 12, 2012
    Date of Patent: July 15, 2014
    Assignee: Richtek Technology Corporation, R.O.C.
    Inventors: Chia-Wei Liao, Jing-Meng Liu, Leng-Nien Hsiu, Pei-Yuan Chen