Fairchild Korea Semiconductor Ltd.

Fairfield Korea Semiconductor Ltd.

Kyung-Oun Jang

Min-Woo Lee

Sung-Won Yun

Won-Tae Lee

Dae-Woong Cho

Eung-Suen Kim

Sun-Hak Lee

Chang-Ho Kim

Hyun-Chul Eum

In-Ki Park

Dae-Bong Kim

Gyoung-Soo Park

Dong-Myeong Shin

Hyeong-Seok Baek

Se-Hwan Kim

A power supply device includes a power switch, a power delivering means configured to convert an input in accordance with switching operation of the power switch and output a result, and a switch control circuit configured to linearly control switching frequency of the power switch in accordance with an output detection voltage corresponding to an output voltage according to the output.

Power supply device capable of varying switching frequency according to load condition

Embodiment relates to a switch control circuit, a switch control method, and a power supply using the switch control circuit. The power supply supplies power to a load using an input voltage. The switch control circuit controls a switching operation of the power switch that controls the power supply. The switch control circuit detects a duty of the power switch using a signal for controlling the switching operation of the power switch, detects the load using the feedback voltage, and determines a short-circuit of the sense resistor according to the detected duty and the detected load.

Switch control circuit, switch control method and power supply device using the same

The present invention relates to a switching mode power supply and a driving method thereof. In the present invention, a supply voltage is generated by using a start voltage that corresponds to input power, and a switching operation frequency of a power switch is changed according to an increase/decrease of the supply voltage.

Switching mode power supply with variable switching operation frequency and the driving method thereof

The present invention relates to a gate driving circuit, a switch control circuit including the gate driving circuit, and a power supply. The gate driving circuit generates a gate voltage of the power switch. The gate driving circuit includes: a delay control circuit generating a first control signal that controls a rising slope of the gate voltage at a first time after a first delay period is passed from a rising time of the gate voltage and generating a second control signal that controls the rising slope of the gate voltage at a time after a second delay period is passed from the first time; and a temperature compensation circuit that varies the first delay period according to a temperature.

Gate driver, switch control circuit and power supply device comprising the gate driver circuit

The present invention relates to a switch controller, a switch control method, and a power supply using the switch controller. A switch controller controls switching operation of a power switch and receives a sense voltage of a sense resistor to which a drain current flowing in the power switch flows. The switch controller generates a sum signal using the sense voltage and a ramp signal having a cycle that is the same as a switching cycle of the power switch. The switch controller determines short-circuit of the sense resistor by detecting slope variation of the sum signal.

Switch controller, switch control method, and power supply device comprising the switch controller

The present invention relates to a thermal shutdown unit, a switch controller including the same, and a method controlling a thermal shutdown protection operation. The present invention determines the operation state of an SMPS to vary a reference temperature for controlling a thermal shutdown protection operation according to an operation state of the SMPS.

Thermal shutdown unit, switch controller including the same, and control method of thermal shutdown protection operation

The present invention relates to a power supply device generating an output power by using an AC line voltage generated through rectification of an AC input, and a driving method thereof. The power supply device controls the switching operation of the power switch by using a sensing voltage corresponding to the drain current flowing to the power switch and the feedback voltage corresponding to the output voltage. The power supply device controls the feedback current every switching cycle to generate a threshold voltage, and compares the sensing voltage and the threshold voltage to control the turn-off of the power switch. The feedback current includes the first current to generate the feedback voltage, and the threshold voltage follows a curved line waveform in which the increasing slope is decreased during the switching cycle.

Power supply device and driving method thereof

In an EMI canceller, a control signal generation unit includes a counter, a second flip-flop, and a multiplexer. The counter outputs first and second output signals and includes first flip-flops in series. An output of the first flip-flop reverses at every cycle of the first and second output signals of a previous first flip-flop. An output of the second flip-flop reverses at every cycle of the first or second output signal of a final first flip-flop. The second flip-flop outputs third and fourth output signals. The multiplexer passes the first output signals of the first flip-flop as a control signal when the third output signal is a first level, and passes the second output signals as the control signal when it is a second level.

EMI cancellation method and system

A switching mode power supply includes a rectifier configured to convert AC power to a first DC power, an output unit configured to convert the first DC power to a second DC power under the control of a first switch, and a pulse width modulation generator coupled to control the first switch. The pulse width modulation generator has a regulator configured to regulate the first DC power. The regulated first DC power powers the pulse width modulation generator. The regulator includes a second switch coupled to control a transmitter so that when the second switch is in a first state the transmitter transmits the first DC power to a capacitor to charge the capacitor to thereby increase the regulated first DC power, and when the switch is in a second state the transmitter does not transmit the first DC power to the capacitor to thereby allow the charge in the capacitor to reduce and in turn the regulated first DC power to reduce.

Pulse width modulation signal generator and switching mode power supply including the same

A CMOS transistor is provided having a relatively high breakdown voltage. The CMOS transistor includes an N-type epitaxial layer on a P-type substrate. Between the substrate and epitaxial layer are a heavily doped N-type buried layer and a heavily doped P-type base layer. An N-type sink region is proximate the edge of the NMOS region, and twin wells are in the area surrounded with the sink region. N+ source and drain regions are formed in respective wells. As the sink region is interposed between the drain and isolation regions, a breakdown occurs between the sink and isolation regions when a high voltage is applied. Twin wells are also formed in the PMOS region. P+ source and drain regions are formed in respective wells. As the N-type well surrounds the source and bulk regions, a breakdown occurs between a buried region and the isolation region when a high voltage is applied.

MOS transistor and fabrication method thereof

A CMOS transistor is provided having a relatively high breakdown voltage. The CMOS transistor includes an N-type epitaxial layer on a P-type substrate. Between the substrate and epitaxial layer are a heavily doped N-type buried layer and a heavily doped P-type base layer. An N-type sink region is proximatethe edge of the NMOS region, and twin wells are in the area surrounded with the sink region. N&plus; source and drain regions are formed in respective wells. As the sink region is interposed between the drain and isolation regions, a breakdown occurs between the sink and isolation regions when a high voltage is applied. Twin wells are also formed in the PMOS region P&plus; source and drain regions are formed in respective wells. As the N-type well surrounds the source and bulk regions, a breakdown occurs between a buried region and the isolation region when a high voltage is applied.

A high efficiency switching controller for use in a switching power supply (SPS) includes a current control device coupled to a voltage source of the SPS and a switch connected between the current control device and an output voltage circuit of the SPS. An under voltage lockout regulator coupled to the output voltage circuit of the SPS and the switch controls the state of the switch based on a voltage of the output voltage circuit and a bias unit coupled to the under voltage lockout regulator provides current to circuitry within the switching controller based on the voltage of the output voltage circuit. A protector within the high efficiency switching controller provides a control signal to the pulse width modulator unit to control the gate drive signal in response to an operating condition of the switching controller. Additionally, the control signal can periodically enable the pulse width modulator unit in response to a voltage of the output voltage circuit so that the gate drive signal includes groups of gate drive pulses.

High efficiency switching controller

A switching power supply having a high efficiency starting circuit uses a field effect transistor to provide initial starting current to a pulse width modulated signal generator within a switching control circuit. The field effect transistor (FET) has a drain connected to a source of supply voltage, a source connected to the PWM signal generator, and a gate connected to a feedback voltage that is derived from an output voltage of the switching power supply. During start up of the switching power supply, the FET provides current to the PWM signal generator. When the feedback voltage reaches a predetermined level, the FET supplies substantially near zero current to the PWM signal generator, thereby eliminating the electrical inefficiencies typically associated with a conventional switching power supply starting circuit.

Growing community of inventors

Bucheon-si, South Korea

Kyung-Oun Jang