Fairchild Korea Semiconductor Ltd.

Dong-Young Huh

Jung-Won Kim

Jin-Ho Choi

Dong-Hee Kim

Sang-Woo Lee

Jae-Soon Choi

Young-Chul Ryu

Jong-Woon Hong

Yong-Jin Joo

Jea-Gon Seo

Jung-Yul Yun

Yong-Chul Ryu

A switching mode power supply (SMPS) is presented to compensate for variations of maximum output power caused by variations of input power. The output power varies according to variations of input power because of a propagation delay of the SMPS. To compensate for the propagation delay, a reference voltage for turning off a switching MOS transistor is differently established depending on the input voltage. The variation of maximum output power according to the input voltage is prevented by differentiating the turned-off time of the reference voltage for turning off a main switch, such as a switching MOS transistor according to the input voltage.

Switching mode power supply

In one embodiment, a switching mode power supply (SMPS) include: a power supply for supplying power to a secondary coil of a transformer according to an operation of a main switch, the main switch being coupled to a primary coil of the transformer; a feedback circuit for generating a feedback voltage corresponding to an output voltage; a control module for stopping the main switch when the feedback voltage is lower than a reference voltage in a standby operation mode; an integrated circuit (IC) power unit for generating a constant voltage, the IC power supply being coupled to the secondary coil of the transformer; and a current generator for using the constant voltage to generate a plurality of constant currents for operating a plurality of ICs, and generating a constant current from among the constant currents when the main switch performs no switching on/off operation.

A switching mode power supply is described. The switching mode power supply includes a power supply unit, a mode setting unit, a feedback circuit, and a switching controller. The switching controller controls a main switch to carry out a switching operation at a predetermined duty according to feedback voltage charged in a first capacitor in the normal operation mode, and controls the main switch to repeat a switching on state and a switching off state in the standby mode. The current inputted to the switching controller varies with the operation mode. Accordingly, the minimum voltage for operating the switching controller can be maintained even if output voltage is decreased in the standby mode, and unnecessary power consumption in the switching controller can be reduced.

Switching mode power supply for low power operation

A switched-mode power supply (SMPS) that operates in a burst mode when an electronic device that receives power from the SMPS demands a low level of power as when in a stand-by mode or cut-off mode. The SMPS contains a first power supply unit for receiving a power and rectifying it, and, according to a level of an output for the load, distinguishing between a normal mode and a burst mode to perform switching according to a timing corresponding to the normal mode and the burst mode to supply a first power. The SMPS also contains an output power supply unit for receiving the first power from the first power supply unit according to a winding ratio of a coil to generate a power for driving the load.

Switched-mode power supply supporting burst-mode operation

A switching power supply includes a switch, a bias-sensor to sense the switch-voltage, and a zero-crossing detector (ZCD) to sense time instances when the bias-sensor voltage crosses zero. ZCD generates a ZCD-signal, which transitions between a first and a second level at the sensed crossing instances, with a delay. ZCD-signal is coupled to a blanking circuit, generating a blank-signal and a pulse-signal, controlling the switch. The on-time of the switch can be modified by the input voltage and load. The blank-signal between on-times is adjusted to compensate for this modification, keeping the switching frequency below a predetermined limit and reducing the switching frequency. The switching power supply further includes a pulse width modulation (PWM) signal generator, coupled to the blanking circuit and to the switch. PWM signal generator turns on the switch controlled by the pulse-signal of the blanking circuit. Blanking circuit is controlled by either the on-time or a control voltage and input voltage.

Switching power supply device and method

An inverter driver comprises: an inverter circuit including first and second switches, inverting DC components into AC components in response to switching by the first and second switches to drive a load; a control signal supply outputting a first voltage corresponding to a voltage caused by sensing the current flowing to the load, and outputting a second voltage, and a third voltage generated by multiplying the first voltage by a gain; a frequency controller including a capacitor and an oscillator, controlling a first current charged in/discharged from the capacitor through the oscillator in response to the first voltage; and a duty controller comparing the third voltage and a fourth voltage charged in the capacitor, and controlling the duty of the first and second switches.

Inverter driver and method

A flyback converter detects an output voltage at the primary coil without using a photo coupler and provides an essentially constant output voltage independent of the load size, thereby minimizing the number of additional coils used in the transformer circuit to realize simple construction and providing accurate power control. In one embodiment, the flyback converter includes: a transformer for changing an input voltage to a predetermined level according to a winding ratio; an output unit for rectifying the voltage signal output from the transformer into a DC signal to drive a load; a switch coupled to the primary coil of the transformer for controlling the on/off state of a power at the primary coil according to a switching control signal; a feedback unit generating a feedback signal and detecting a current of the switch to correct the feedback signal; and a switching controller operating according to the feedback signal.

Flyback converter

An electronic lamp dimmer includes a burst dimmer circuit and an analog dimmer circuit formed adjacent to each other on an integrated circuit substrate. The burst dimmer circuit controls the illumination intensity of a lamp over a first operating range and the analog dimmer circuit controls the illumination intensity of the lamp over a second operating range that overlaps the first operating range. The electronic dimmer includes a plurality of electrical contacts, each of which is electrically coupled to one of the burst dimmer and analog dimmer circuits and one of which simultaneously provides a dimming control voltage to both of the burst dimmer and analog dimmer circuits.

Dual mode electronic dimmer

A switching power supply includes a power switch and a mode controller that provides a mode control signal having a first level associated with a normal mode of operation of the switching power supply and a second level associated with a standby mode of operation of the switching power supply. The switching power supply further includes a feedback circuit coupled to the mode controller and a switching controller coupled to the feedback circuit. The feedback circuit has a voltage controlled current source that provides a feedback current which varies in response to the mode control signal. The switching controller switches the power switch in response to the feedback current so that in the normal mode of operation the power switch switches continuously at a predetermined frequency and in the standby mode of operation the power switch is switched on and off in bursts having a predetermined frequency.

Growing community of inventors

Bucheon, South Korea

Dong-Young Huh