Patents Assigned to Richtek Technology Corporation
  • Patent number: 10476374
    Abstract: The present invention discloses a short circuit and/or bad connection detection method for use in a power supply system. The power supply system includes a power converter which converts an input voltage to an output voltage and supplies an output current to an electronic device. In the short circuit detection method, the conversion from the input voltage to the output voltage is disabled in a disable time period, and whether a short circuit occurs is determined according to the decreasing speed of the output voltage. In the bad connection detection method, an actual voltage and an actual current received by the electronic device are compared with the output voltage and the output current, to determine whether a bad connection occurs.
    Type: Grant
    Filed: October 22, 2018
    Date of Patent: November 12, 2019
    Assignee: RICHTEK TECHNOLOGY CORPORATION
    Inventors: Yi-Min Shiu, Isaac Y. Chen
  • Patent number: 10476275
    Abstract: The present invention provides a multi-load control apparatus, a slave circuit and a control method thereof. The multi-load control apparatus includes a master circuit and at least one slave circuit. The master circuit generates at least one pulse width modulation (PWM) signal according to an input signal. The slave circuit controls a power switch according to a corresponding PWM signal. The slave circuit has a primary side circuit and a secondary side circuit. The primary side circuit generates an AC PWM signal according to the corresponding PWM signal. The power switch has a control terminal which is driven according to a floating ground level which is not a constant voltage level. The power switch has a current inflow terminal and a current outflow terminal, which are connected to a corresponding load circuit in series, wherein the series circuit of the power switch and the load circuit receives an AC voltage.
    Type: Grant
    Filed: October 4, 2016
    Date of Patent: November 12, 2019
    Assignee: RICHTEK TECHNOLOGY CORPORATION
    Inventors: Chang-Yu Wu, Yi-Wei Lee
  • Patent number: 10476257
    Abstract: An interface control circuit comprises an interface signal transceiver circuit coupled with an interface which includes at least one interface pin for transmitting and/or receiving an interface signal through the interface, and a protection circuit for generating a protection control signal according to a capacitance of a first interface pin. During a predetermined detection time period starting from an attaching event, the protection circuit senses the capacitance of the first interface pin, and determines that there is an electrolytic substance existing and coupled with the first interface pin when the capacitance is larger than a predetermined first capacitance threshold. The protection control signal triggers the interface signal transceiver circuit to execute a protection operation. The interface includes the first interface pin and the second interface pin, and the first interface pin and the second interface pin can be one same pin or separate different pins.
    Type: Grant
    Filed: June 30, 2017
    Date of Patent: November 12, 2019
    Assignee: RICHTEK TECHNOLOGY CORPORATION
    Inventors: Chieh-Min Lo, Yi-Syue Jhu
  • Patent number: 10476499
    Abstract: A power-on reset (POR) circuit includes: a signal generator circuit for generating a first and a second signal according to an input voltage, and a comparator circuit. The comparator circuit, having a non-zero input offset, includes a first MOS transistor with a first conductive type and having a first conductive type gate and a first threshold voltage, and a second MOS transistor with a first conductive type and having a second conductive type gate and a second threshold voltage. The input offset relates to a difference between the first and the second threshold voltage. The first and the second signal control the first and the second MOS transistors respectively to generate a POR signal. When the input voltage exceeds a POR threshold which relates to a predetermined multiple or ratio of the input offset, the POR signal transits its state.
    Type: Grant
    Filed: April 12, 2018
    Date of Patent: November 12, 2019
    Assignee: RICHTEK TECHNOLOGY CORPORATION
    Inventors: Chin-Yuan Wei, Chih-Hsien Wang
  • Patent number: 10466732
    Abstract: A switching regulator includes a power stage circuit and a control circuit. The power stage circuit operates a high-side switch and a low-side switch therein according to a high-side signal and a low-side signal respectively to generate an inductor current flowing through an inductor therein. The adjustment signal generation circuit in the control circuit generates an adjustment level according to the high-side signal, the low-side signal, and/or the inductor current, wherein the adjustment level is switched between a reverse recovery level and an anti-latch-up level, and is electrically connected to a low-side isolation region of the low-side switch. The reverse recovery level is lower than the input voltage. The anti-latch-up level is higher than the reverse recovery level to avoid a latch-up effect.
    Type: Grant
    Filed: February 12, 2019
    Date of Patent: November 5, 2019
    Assignee: RICHTEK TECHNOLOGY CORPORATION
    Inventors: Chien-Yu Chen, Tsung-Yi Huang, Ting-Wei Liao
  • Patent number: 10461624
    Abstract: The present invention provides a power switch control circuit and an open detection method thereof. The power switch control circuit is for generating an operation signal at an operation signal output pin according to an input signal, wherein the operation signal is for operating a power switch. The power switch control circuit includes: a current injection circuit, which is connected to the operation signal output pin, and provides a predetermined current to the operation signal output pin according to an enable signal; and an open detection circuit, which is coupled to the current injection circuit, and determines whether a connection between the operation signal output pin and the power switch is open according to a level of the operation signal output pin at a detection time point or according to a level variation of the operation signal output pin during a detection time period, whereby an open detection signal is generated.
    Type: Grant
    Filed: April 11, 2017
    Date of Patent: October 29, 2019
    Assignee: RICHTEK TECHNOLOGY CORPORATION
    Inventors: Pei-Sheng Tsu, Chien-Fu Tang, Isaac Y. Chen
  • Patent number: 10461652
    Abstract: A flyback power converter includes: a transformer, a power switch, a switch control unit, a synchronous rectifier switch and a secondary side control circuit. The secondary side control circuit includes: a switch signal generation circuit and a first power conversion circuit. The secondary side control circuit is coupled to the synchronous rectifier switch and the secondary winding of the transformer. The switch signal generation circuit generates the synchronous rectifier switch signal selectively according to a first power or a second power, to control the synchronous rectifier switch. The first power is related to the output voltage. The first power conversion circuit generates the second power according to a secondary phase signal on a phase node between the secondary winding of the transformer and the synchronous rectifier switch.
    Type: Grant
    Filed: September 15, 2018
    Date of Patent: October 29, 2019
    Assignee: RICHTEK TECHNOLOGY CORPORATION
    Inventors: Chien-Fu Tang, Jo-Yu Wang, Isaac Y. Chen
  • Patent number: 10447082
    Abstract: A wireless power transmitter circuit includes a power inverter circuit, a resonant transmitter circuit and a control circuit. The power inverter circuit converts a DC power to an AC output power which includes an AC output current. The resonant transmitter circuit, including a variable capacitor circuit, converts the AC output power to a resonant wireless power which includes a resonant current. The control circuit generates an impedance control signal according to a resonant current related signal and a current reference signal, for controlling the impedance of the variable capacitor circuit to regulate the resonant current or the AC output current substantially at a predetermined current level.
    Type: Grant
    Filed: May 19, 2017
    Date of Patent: October 15, 2019
    Assignee: RICHTEK TECHNOLOGY CORPORATION
    Inventor: Kuo-Chi Liu
  • Patent number: 10418482
    Abstract: A high voltage device is formed in a semiconductor substrate, and includes: a first deep well, a lateral lightly doped region, a high voltage well, an isolation region, a body region, a gate, a source, a drain, and a first isolation well. The first deep well and the first isolation well are for electrical isolating the high voltage device from neighboring devices below a top surface of the semiconductor substrate. The lateral lightly doped region is located between the first deep well and the high voltage well in a vertical direction, and the lateral lightly doped region contacts the first deep well and the high voltage well. The lateral lightly doped region is for reducing an inner capacitance of the high voltage device when the high voltage device operates, to improve transient response.
    Type: Grant
    Filed: August 7, 2018
    Date of Patent: September 17, 2019
    Assignee: RICHTEK TECHNOLOGY CORPORATION
    Inventor: Tsung-Yi Huang
  • Patent number: 10420179
    Abstract: A driver circuit supplies a positive voltage and a negative voltage to a load. The driver circuit includes: a positive power conversion circuit, coupled to the load, and generating the positive voltage according to an input voltage; a negative power conversion circuit, coupled to the positive power conversion circuit and the load, and generating the negative voltage according to the positive voltage; and a headroom adaptive adjustment circuit, coupled to the positive power conversion circuit and the load, and generating an adjustment signal according to one or more of a load current flowing through the load, the positive voltage Vp and the negative voltage Vn. The adjustment signal is sent to the positive power conversion circuit to adjust a regulation target of the positive voltage.
    Type: Grant
    Filed: November 28, 2018
    Date of Patent: September 17, 2019
    Assignee: RICHTEK TECHNOLOGY CORPORATION
    Inventors: Ching-Yu Chen, Hsing-Shen Huang
  • Patent number: 10411581
    Abstract: A switching power conversion apparatus includes: a multi-level power stage, a PWM control circuit, a multi-level driver circuit, a bootstrap capacitor control circuit and a driving power control circuit. The bootstrap capacitor control circuit includes bootstrap capacitor control switches. During a charging period, a bootstrap control signal controls the bootstrap capacitor control switches, to electrically connect a second bootstrap node to the ground voltage level, whereby the supply voltage charges the bootstrap capacitor via the bootstrap diode. During a pumping period, the bootstrap control signal controls the bootstrap capacitor control switches to electrically connect the second bootstrap node to one of the upper-gate nodes or the switching node, whereby the voltage of the first bootstrap node is pumped to a corresponding pumping voltage level.
    Type: Grant
    Filed: December 14, 2018
    Date of Patent: September 10, 2019
    Assignee: RICHTEK TECHNOLOGY CORPORATION
    Inventors: Wei-Jen Huang, Shun-Yu Huang
  • Patent number: 10396674
    Abstract: A flyback power converter includes a transformer having a primary winding for receiving an input power, a secondary winding for generating an output power, and an auxiliary winding for generating a supply voltage, a primary side switch coupled to the primary winding, a high voltage start-up switch coupled to the input voltage and the controller supply voltage, and a primary side controller powered by the controller supply voltage. The primary side controller includes a multi-function pin coupled to a control terminal of the high voltage start-up switch, a high voltage start-up circuit for controlling the high voltage start-up switch to be ON through the multi-function pin when the controller supply voltage is lower than a threshold, and a protection control circuit which is coupled to an protection sensing signal through the multi-function pin; the protection control circuit operates the flyback power converter according to the protection sensing signal.
    Type: Grant
    Filed: June 29, 2018
    Date of Patent: August 27, 2019
    Assignee: RICHTEK TECHNOLOGY CORPORATION
    Inventor: Kun-Yu Lin
  • Patent number: 10389249
    Abstract: A switching regulator having adjustable inductor current threshold employs a control method which includes: (S1) determining whether an output voltage is greater than a reference voltage or determining whether a switching frequency of the power stage is smaller than a predetermined lower frequency limit, and (S2) when it is determined yes in the step (S1), adjusting the inductor current threshold, such that the switching regulator operates under a pseudo discontinuous conduction mode (PDCM) wherein the switching frequency is not smaller than the predetermined lower frequency limit. Consequently, when the switching regulator operates under a light load mode, an optimum balance between a total power consumption and switching noise interference will be ensured.
    Type: Grant
    Filed: June 15, 2018
    Date of Patent: August 20, 2019
    Assignee: RICHTEK TECHNOLOGY CORPORATION
    Inventors: Hong-Wei Huang, Yu-Kai Lin, Wei-Chuan Wu
  • Patent number: 10356878
    Abstract: A light emitting device driver circuit includes: a power conversion circuit, an error amplifier circuit, a sample-and-hold circuit, a load current generation circuit and a feed-forward capacitor. When the light emitting device driver circuit is in a disable phase, the sample-and-hold circuit connects a feedback signal with a second reference voltage and the sample-and-hold circuit disconnects the feedback signal from a load node, whereby the feed-forward capacitor samples a sample voltage and holds it after the disable phase transits to an enable phase. In the enable phase, the sample-and-hold circuit disconnects the feedback signal from the second reference voltage and the sample-and-hold circuit connects the feedback signal with the load node, so that during a predetermined period following the transition, there is a sufficient difference between two input terminals of the error amplifier circuit so that the load current is raised to a desired current level within the predetermined period.
    Type: Grant
    Filed: November 22, 2018
    Date of Patent: July 16, 2019
    Assignee: RICHTEK TECHNOLOGY CORPORATION
    Inventors: Huan-Chien Yang, Tsung-Wei Huang, Hui-Wen Cheng, Shui-Mu Lin
  • Patent number: 10355088
    Abstract: The present invention provides a MOS (Metal-Oxide-Silicon) device having mitigated threshold voltage roll-off and a threshold voltage roll-off mitigation method therefor. The MOS device includes: a substrate, a well region, an isolation region, a gate, two LDDs (Lightly-Doped-Drains), a source, a drain and a compensation doped region. The compensation doped region is substantially in contact with at least a part of a recessed portion along the channel length direction. Viewing from a cross-section view, at a boundary where the compensation doped region is in contact with the isolation region along the channel length direction, the compensation doped region has two doped region widths along the channel width direction, wherein, the two doped region widths of the compensation doped region are both not greater than 10% of the width of the operation region. Two doped region widths are defined as distances within an interior part and an exterior part of the operation region, respectively.
    Type: Grant
    Filed: June 14, 2017
    Date of Patent: July 16, 2019
    Assignee: RICHTEK TECHNOLOGY CORPORATION
    Inventors: Tsung-Yi Huang, Ying-Shiou Lin
  • Patent number: 10355612
    Abstract: A flyback power converter circuit converting an input voltage to an output voltage includes a transformer, a power switch, a synchronous rectifier (SR) switch, and a secondary side control circuit. The secondary side control circuit controls the SR switch to be ON when the power switch is OFF. The secondary side control circuit includes a driving switch for controlling the SR switch, a synchronous control circuit powered by a voltage related to the output voltage, which controls the driving switch to operate the SR switch, and a clamping circuit including a clamping switch and a clamping switch control circuit. The clamping switch control circuit controls the clamping switch according to a current inflow terminal voltage of the clamping switch and/or the voltage related to the output voltage, such that, during a secondary side power-on period, an equivalent impedance of the current inflow terminal of the clamping switch is smaller than a predetermined clamping impedance.
    Type: Grant
    Filed: January 8, 2018
    Date of Patent: July 16, 2019
    Assignee: RICHTEK TECHNOLOGY CORPORATION
    Inventors: Chien-Fu Tang, Su-Yuan Lin, Yi-Wei Lee, Isaac Y. Chen
  • Patent number: 10326351
    Abstract: A switching regulator includes: a controller power ON reset (POR) circuit, a controller post-POR signal generation circuit, and a pulse width modulation (PWM) signal generation circuit. The controller post-POR signal generation circuit switches the controller post-POR signal to a ready level after a controller pre-POR signal is switched to a controller reset-accomplished level and a driver signal starts switching levels to operate a power switch. The PWM signal generation circuit sets a duty ratio of a PWM signal to a predetermined minimum duty ratio after the controller pre-POR signal is switched to the controller reset-accomplished level and before the controller post-POR signal is switched to a ready level.
    Type: Grant
    Filed: September 6, 2018
    Date of Patent: June 18, 2019
    Assignee: RICHTEK TECHNOLOGY CORPORATION
    Inventors: Li-Di Lo, Isaac Y. Chen, Chien-Fu Tang
  • Patent number: 10325981
    Abstract: A high-side device includes: a substrate, an epitaxial layer, a high voltage well, a body region, a gate, a source, a drain, two buried regions. A PN junction is formed between the body region and the high voltage well, wherein the PN junction is perpendicular to a channel direction. One buried region is formed in the epitaxial layer and has a first conductive type, wherein an inner side boundary thereof is located between the drain and the PN junction. The other buried region is formed in the substrate and in the epitaxial layer and has a second conductive type, wherein an inner side boundary thereof is located between the drain and the PN junction. The impurity concentration of the second buried region is sufficient to prevent the high voltage well between the PN junction and the drain from being completely depleted when the high-side power device is ON.
    Type: Grant
    Filed: March 1, 2018
    Date of Patent: June 18, 2019
    Assignee: RICHTEK TECHNOLOGY CORPORATION
    Inventor: Tsung-Yi Huang
  • Patent number: 10326016
    Abstract: 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.
    Type: Grant
    Filed: July 17, 2018
    Date of Patent: June 18, 2019
    Assignee: RICHTEK TECHNOLOGY CORPORATION
    Inventor: Tsung-Yi Huang
  • Patent number: 10320304
    Abstract: The present invention provides a power converter, a secondary side controller, and a short circuit determination method for a current sensing resistor of the power converter. The power converter is controlled by a power switch to convert an input voltage to an output voltage, and provide an output current to an output terminal. The power converter senses the output current by a current sensing resistor to generate first information which relates to the output current. The power converter generates second information according to an ON time, an OFF time or a switching period of the power switch, or according to an energy-releasing period for transmitting energy to the output terminal, wherein the second information indicates whether there is a substantial amount of energy transmitted to the output terminal. By checking whether the first information and the second information are contradictory to each other, a malfunction can be found.
    Type: Grant
    Filed: October 11, 2016
    Date of Patent: June 11, 2019
    Assignee: RICHTEK TECHNOLOGY CORPORATION
    Inventors: Yu-Kai Chen, Kuang-Fu Chang