Patents Assigned to Chengdu Monolithic Power Systems Co., Ltd.
  • Dimming mode detection method used in LED driving apparatus
    Patent number: 9282610
    Abstract: A dimming mode detection method is used in an LED driving apparatus including a rectifier bridge providing a DC bus voltage and a switching converter configured to convert the DC bus voltage into a driving signal to drive an LED. The method involves: powering on the LED driving apparatus; sensing the DC bus voltage and generating a voltage sensing signal; comparing a rising time during which the voltage sensing signal increases from a second threshold voltage to a first threshold voltage with a first time threshold to detect whether the LED driving apparatus is connected to a leading edge dimmer; and comparing a falling time during which the voltage sensing signal decreases from a third threshold voltage to a fourth threshold voltage with a second time threshold to detect whether the LED driving apparatus is connected to a trailing edge dimmer.
    Type: Grant
    Filed: June 12, 2015
    Date of Patent: March 8, 2016
    Assignee: Chengdu Monolithic Power Systems Co., Ltd.
    Inventors: Naixing Kuang, Jiali Cai, Lin Feng
  • Dimmer compatible LED driving apparatus with adjustable bleeding current
    Patent number: 9282609
    Abstract: An LED driving apparatus includes a rectifier bridge generating a DC bus voltage, a bus capacitor coupled between the output terminal of the rectifier bridge and a reference ground, a voltage sensing circuit generating a voltage sensing signal indicative of the DC bus voltage, a bleeding circuit providing a bleeding current for the bus capacitor, a switching converter configured to convert the DC bus voltage into a driving signal to drive an LED, a dimming mode detector detecting whether the LED driving apparatus is coupled to a leading edge dimmer or a trailing edge dimmer based on the voltage sensing signal, and a bleeding control circuit generating a control signal to control the bleeding circuit based on the voltage sensing signal, the leading edge dimming mode signal and the trailing edge dimming mode signal.
    Type: Grant
    Filed: June 12, 2015
    Date of Patent: March 8, 2016
    Assignee: Chengdu Monolithic Power Systems Co., Ltd.
    Inventors: Naixing Kuang, Jiali Cai, Lin Feng
  • Digital controllers and digital control methods of multi-phase switching converters
    Patent number: 9270178
    Abstract: A method for controlling a multi-phase switching converter with a plurality of switching circuits, including: sensing the output current of the switching circuit and generating a current sensing signal; generating a digital phase current signal based on the current sensing signal; subtracting the digital phase current signal from a current reference signal and generating a current error signal; proportionally integrating the current error signal and generating a first bias signal; conducting a sigma-delta modulation of the first bias signal and generating a second bias signal, wherein the first bias signal is a P-bit digital signal, the second bias signal is a Q-bit digital signal, and P is larger than Q; and adjusting a control signal controlling the switching circuit based on the second bias signal.
    Type: Grant
    Filed: December 13, 2013
    Date of Patent: February 23, 2016
    Assignee: Chengdu Monolithic Power Systems Co., Ltd.
    Inventors: Lijie Jiang, Xiaokang Wu, Suhua Luo, Qian Ouyang
  • Multi-phase switching converter with over current protection and control method thereof
    Patent number: 9263876
    Abstract: A multi-phase switching converter includes a plurality of switching circuits and a controller. The output terminals of the plurality of switching circuits are coupled together to provide an output voltage to a load. The controller is configured to generate a plurality of control signals to control the plurality of switching circuits. When an over current condition of a current switching circuit of the plurality of switching circuits is detected, the controller skips the current switching circuit and successively turns on the remaining plurality of switching circuits that have not yet been turned on and where an over current condition has not been detected.
    Type: Grant
    Filed: July 17, 2013
    Date of Patent: February 16, 2016
    Assignee: Chengdu Monolithic Power Systems Co., Ltd.
    Inventors: Lijie Jiang, Xiaokang Wu, Qian Ouyang
  • LED power supply with small dimming ratio control and control method thereof
    Patent number: 9265110
    Abstract: A LED driving control circuit for controlling a power switch in a LED power supply includes: a feedback circuit coupled to a LED load and generating a feedback signal indicative of an output voltage of the LED power supply; an enabling circuit generating an enable signal according to the feedback signal, a first reference signal and a PWM dimming signal, wherein when the feedback signal is higher than the first reference signal, the enable signal synchronizes with the PWM dimming signal, and when the feedback signal is lower than the first reference signal, the duty cycle of the enable signal is higher than the duty cycle of the PWM dimming signal; and a feedback loop control circuit generating a control signal for controlling the power switch according to the feedback signal only when the enable signal is in an active state.
    Type: Grant
    Filed: December 23, 2014
    Date of Patent: February 16, 2016
    Assignee: Chengdu Monolithic Power Systems Co., Ltd.
    Inventor: Zhijiang Yang
  • Load detecting circuits and the method thereof
    Patent number: 9252766
    Abstract: A no-load detecting circuit and the method thereof are disclosed. The no-load detecting circuit may be applied in switching mode power supplies or other circuits. The no-load detecting circuit comprises: a variable resistance circuit coupled in series to a load of the switching mode power supply; and a first comparison circuit coupled to the variable resistance circuit to receive the voltage across the variable resistance circuit, wherein based on the comparison of the voltage across the variable resistance circuit and a first threshold, the first comparison circuit generates a no-load detecting signal indicative of the load status; wherein the equivalent resistance of the variable resistance circuit varies based on the varying of the load of the switching mode power supply.
    Type: Grant
    Filed: June 29, 2012
    Date of Patent: February 2, 2016
    Assignee: Chengdu Monolithic Power Systems Co., Ltd.
    Inventors: Yuancheng Ren, En Li, Naixing Kuang, Yike Li
  • One-time programmable memory cell and circuit
    Patent number: 9245647
    Abstract: An OTP memory cell and an OTP memory circuit. The OTP memory cell having a memory module, a write module, a read module, and a load module. Data may be written into the memory module once the write module is active; and data may be read out of the memory module once the read module is active. The OTP memory cell may also have a first latch module and a second latch module.
    Type: Grant
    Filed: June 30, 2014
    Date of Patent: January 26, 2016
    Assignee: Chengdu Monolithic Power Systems Co., Ltd.
    Inventors: Eric Braun, Da Chen
  • LED driving circuit, control circuit and associated current sensing circuit
    Patent number: 9241381
    Abstract: A LED driving circuit, a control circuit and associated current sensing circuit. The control circuit has a sensing circuit, an estimation circuit, an amplifying circuit, a comparing circuit, a zero-cross detection circuit and a logic circuit. The sensing circuit is configured to sense a switching current flowing through at least one switch of a switching circuit to provide a first sensing signal. The estimation circuit is configured to process the first sensing signal to provide a feedback signal, wherein the feedback signal is indicative of a average current signal flowing through a LED. An average current flowing through the LED is regulated by sensing a switching current flowing through at least one switch.
    Type: Grant
    Filed: December 30, 2014
    Date of Patent: January 19, 2016
    Assignee: Chengdu Monolithic Power Systems Co., Ltd.
    Inventors: Lin Feng, Yuedong Chen
  • Charge pump and method of having negative output voltage tracking positive output voltage thereof
    Patent number: 9236796
    Abstract: A method having a negative output voltage at a negative output terminal of a charge pump tracking a positive output voltage at a positive output terminal of the charge pump. The charge pump comprises a plurality of switches and each of the plurality of switches has a serially coupled resistance. The method comprises selecting the serially coupled resistance for at least one of the plurality of switches to be different to each of the other respective serially coupled resistances associated to the other switches.
    Type: Grant
    Filed: May 29, 2014
    Date of Patent: January 12, 2016
    Assignee: Chengdu Monolithic Power Systems Co., Ltd.
    Inventors: Bairen Liu, Hongqiang Qin, Eric Yang, Song Qu, Paul Ueunten
  • Switch mode power supply, control circuit and associated control method
    Patent number: 9236801
    Abstract: A switch mode power supply having an output terminal configured to provide an output voltage, the switch mode power supply has a first switch, a second switch and a control circuit. The control circuit is configured to provide a first switching control signal to turn ON and turn OFF the first switch, and when the switch mode power supply works in a power saving mode, the first switch is turned ON if a voltage feedback signal is less than a reference voltage and a current flowing through the second switch is less than a bias current.
    Type: Grant
    Filed: December 10, 2013
    Date of Patent: January 12, 2016
    Assignee: Chengdu Monolithic Power Systems Co., Ltd.
    Inventor: Qian Ouyang
  • Power converter, clock module and associated control method
    Patent number: 9231574
    Abstract: A power converter and a clock module employed for providing a clock signal to the power converter. The power converter converts an input voltage to an output voltage based on at least the switching on and off of a main switch. The clock module monitors a deviation of the output voltage from its desired value and compares the deviation with a predetermined threshold window to provide a clock control signal. The clock module further regulates the clock signal in response to the clock control signal.
    Type: Grant
    Filed: September 5, 2014
    Date of Patent: January 5, 2016
    Assignee: Chengdu Monolithic Power Systems Co., Ltd.
    Inventors: James Nguyen, Yike Li
  • Switch-mode power supply, control circuit and associated dimming method
    Patent number: 9232606
    Abstract: A switch-mode power supply and associated control circuit for a light-emitting device are disclosed. The switch-mode power supply having a first switch which is turned ON or OFF by a control signal. The control circuit having an error amplifier, a minimum-off time control circuit and a logic circuit, wherein the error amplifier is configured to provide a compensation signal based on a dimming signal and a feedback signal. The minimum-off time control circuit is configured to provide a minimum-off time control signal to adjust a minimum-off time period of the first switch based on the compensation signal. The logic circuit is configured to provide the control signal based on the minimum-off time control signal.
    Type: Grant
    Filed: November 21, 2012
    Date of Patent: January 5, 2016
    Assignee: Chengdu Monolithic Power Systems Co., Ltd.
    Inventor: Naixing Kuang
  • Failure detector circuit and associated method
    Patent number: 9219468
    Abstract: A failure detector circuit for detecting status of a protected circuit, the failure detector circuit having an operating cycle, has an enabling signal generator, a comparator circuit, a delay circuit. The enabling signal generator enables the comparator for an enable time in each operating cycle. The comparator circuit compares an output of the protected circuit with a reference signal. The delay circuit receives an output signal of the comparator to decide whether a failure occurred within a give delay time.
    Type: Grant
    Filed: December 7, 2012
    Date of Patent: December 22, 2015
    Assignee: Chengdu Monolithic Power Systems Co., Ltd.
    Inventors: Jiangyun Zhou, Yike Li
  • LED backlight driver system and associated method of operation
    Patent number: 9215769
    Abstract: The embodiments of the present circuit and method disclose a light-emitting diode (LED) driver system. The LED driver system may comprise an isolated converter and a DC/DC converter. The isolated converter may be coupled to a first input signal, and may provide a LED current and a bus voltage. The isolated converter may be configured to regulate the LED current and the bus voltage separately in accordance with a dimming signal. The DC/DC converter may comprise an input coupled to the bus voltage.
    Type: Grant
    Filed: January 25, 2012
    Date of Patent: December 15, 2015
    Assignee: Chengdu Monolithic Power Systems Co., Ltd.
    Inventors: Frank Ren, Naixing Kuang, Bairen Liu, Licheng Sheng
  • AC signal detector and the method thereof
    Patent number: 9201102
    Abstract: An AC signal detector having: a rectify circuit having a first input terminal and a second input terminal configured to receive an AC signal, and an output terminal configured to provide a rectified signal based on the AC signal; a detecting circuit having an input terminal coupled to the output terminal of the rectify circuit to receive the rectified signal, and an output terminal configured to provide a square signal based on the rectified signal; and an unplug indicate circuit having an input terminal coupled to the detecting circuit to receive the square signal, and an output terminal configured to provide an unplug indicate signal based on the square signal.
    Type: Grant
    Filed: June 28, 2013
    Date of Patent: December 1, 2015
    Assignee: Chengdu Monolithic Power Systems Co., Ltd.
    Inventors: Siran Wang, Yike Li, Kun Yi, Yuancheng Ren, Junming Zhang, En Li
  • Phase-shift dimming for LED controller and the method thereof
    Patent number: 9179519
    Abstract: A phase-shift dimming circuit for LED controller having a delay signal generator configured to receive a PWM input signal, and to provide a plurality of pairs of set signal and reset signal, the set signal and the reset signal respectively having pulses; and a plurality of latches configured to respectively receive the plurality of pairs of set signal and reset signal to generate a plurality of PMW output signals, each of the PWM output signals having pulses, and wherein the rising edge of the pulses of the PWM output signals is based on the corresponding set signal pulses, and the falling edge of the pulses of the PWM output signals is based on the corresponding reset signal pulses.
    Type: Grant
    Filed: December 27, 2012
    Date of Patent: November 3, 2015
    Assignee: Chengdu Monolithic Power Systems Co., Ltd.
    Inventors: Da Chen, Zhengwei Zhang, Kaiwei Yao
  • Charge-pump voltage divider and associated control method
    Patent number: 9172300
    Abstract: The embodiments of the present invention disclose a charge-pump voltage divider and associated start-up method. The charge-pump voltage divider comprises a start-up circuit that can regulate an inrush current during start up. The start-up circuit comprises a switch, which operates in linear region state during start-up, and operates in switching state after the start-up completes. The charge-pump voltage divider may further comprise a load control switch configured to ensure the start-up is independent of a load current.
    Type: Grant
    Filed: May 9, 2013
    Date of Patent: October 27, 2015
    Assignee: Chengdu Monolithic Power Systems Co., Ltd.
    Inventors: Taofeng Li, Yike Li
  • Discharge circuits for EMI filters capacitors and methods thereof
    Patent number: 9148049
    Abstract: A discharge circuit for an EMI filter capacitor, wherein the EMI filter capacitor is coupled between input terminals of a switching converter. The discharge circuit has a detecting circuit and a current source. The detecting circuit is configured to detect whether an electrical source is coupled to the input terminals of the switching converter. The current source is coupled between the input terminals of the switching converter and a power supply capacitor, and is configured to provide a power supply voltage across the power supply capacitor. When the electrical source is uncoupled from the input terminals of the switching converter, the EMI filter capacitor is discharged by the current source.
    Type: Grant
    Filed: March 11, 2013
    Date of Patent: September 29, 2015
    Assignee: Chengdu Monolithic Power Systems Co., Ltd.
    Inventor: En Li
  • Power factor correction circuit, the control circuit and the method thereof
    Patent number: 9130473
    Abstract: A power factor correction circuit including a rectifier bridge, an energy storage component, a power switch, a second switch and a control circuit provides reduced THD and improved PF performance under a high input AC voltage.
    Type: Grant
    Filed: June 27, 2013
    Date of Patent: September 8, 2015
    Assignee: Chengdu Monolithic Power Systems Co., Ltd.
    Inventors: Sicong Lin, Lianfeng Ding, Zhengxing Li
  • Switching power converter and control method thereof
    Patent number: 9118258
    Abstract: A switching power converter with an input terminal configured to receive a first input voltage; an output terminal configured to provide an output current to a load, wherein the output current has a peak value and an average value; a power switch; a first loop coupled to the input terminal, wherein the first loop configured to generate a first output signal based on the first input voltage; a second loop configured to generate a second output signal based on the output current; a multiplier configured to generate a multiplying signal based on multiplying the first output signal with the second output signal; and a driving circuit configured to generate a driving signal based on the multiplying signal to control the power switch, so as to reduce the ratio between the peak value and the average value of the output current.
    Type: Grant
    Filed: September 14, 2012
    Date of Patent: August 25, 2015
    Assignee: Chengdu Monolithic Power Systems Co., Ltd.
    Inventors: Yike Li, Paul Ueunten