Patent application number | Description | Published |
20090001939 | APPARATUS FOR PREVENTING CAPACITOR CHARGER FROM OVERCHARGING AND METHOD THEREOF - An apparatus for controlling a charging circuit is provided. The apparatus includes a first detector, a second detector, and a controller. The first detector detects a voltage level at a first time and generates a first indication value corresponding to the voltage level at the first time, where the voltage level corresponds to an output voltage of the charging circuit. The second detector detects the voltage level at a second time after the first time and generates a second indication value corresponding to the voltage level at the second time. The controller receives the first and second indication values, and generates a control signal according to the first and second indication values for turning the charging circuit on and off. | 01-01-2009 |
20090091950 | POWER CONVERTING CIRCUIT WITH OPEN LOAD PROTECTION FUNCTION - A power converting circuit with an open load protection function is electrically connected to a power supply providing a first voltage level, and outputs a second voltage level to drive a load. The power converting circuit includes a DC/DC converter and a rectifying element disposed between an output node and an input node of the DC/DC converter that forms a discharging loop with the DC/DC converter. The DC/DC converter receives the power, converts the first voltage level into the second voltage level and outputs the second voltage level to the load. The rectifying element is utilized to release a surge voltage produced by the DC/DC converter in an open load condition. | 04-09-2009 |
20090115390 | POWER CONVERTER WITH PROTECTION MECHANISM FOR DIODE IN OPEN-CIRCUIT CONDITION AND PULSE-WIDTH-MODULATION CONTROLLER THEREOF - A power converter with a protection mechanism for a diode in an open-circuit condition includes a DC to Dc (DC/DC) conversion circuit, a detection and protection circuit, a pulse-width-modulation (PWM) signal generator, and a logic gate. The detection and protection circuit is used for detecting an open-circuit condition of the diode of the DC/DC conversion circuit. The logic gate receives an output signal of the detection and protection circuit and a PWM signal outputted by the PWM signal generator. When the diode is in an open-circuit condition, the PWM signal cannot be transmitted to a power switch of the DC/DC conversion circuit due to the output signal of the detection and protection circuit. | 05-07-2009 |
20090121674 | CHARGING DEVICE WITH BOUNDARY MODE CONTROL - A charging device with boundary mode control is disclosed. The charging device includes a transformer, a power switch, a detection circuit and a pulse-width modulation (PWM) controller. The power switch is electrically connected to one end of a primary-side winding of the transformer. The detection circuit is electrically connected to the primary-side winding and the power switch. The detection circuit detects the resonance of the parasitic capacitance of the power switch, thereby generating a detection signal for boundary mode control. The PWM controller generates a pulse-width modulation signal for driving the power switch, and turns on the power switch according to the detection signal. | 05-14-2009 |
20090128209 | PULSE WIDTH MODULATION CONTROL CIRCUIT APPLIED TO CHARGE OUTPUT CAPACITOR - A pulse width modulation (PWM) control circuit is applied to a power converter with a charging capacitor. The PWM control circuit includes a PWM signal generator, a first comparator, and a reference voltage modulator. A PWM signal generator generates a PWM signal to control a power switch in the power converter. Two input terminals of the first comparator respectively receive a first reference voltage and a sensing voltage, which is proportional to a primary-side current of a transformer. When the power switch is turned on and the sensing voltage rises to the level of the first reference voltage, the first comparator outputs a first control signal to the PWM signal generator. Then, the PWM signal generator outputs a signal to turn off the power switch. The reference voltage modulator outputs the first reference voltage according to a feedback voltage relative to the output voltage of the power converter. | 05-21-2009 |
20090146575 | Light Emitting Diode (LED) Driving Device - A light emitting diode (LED) driving device includes a power factor correction (PFC) circuit, a bridge switch circuit, a resonant circuit, a transformer and a feedback circuit. The PFC circuit adjusts an output signal thereof based on a feedback signal. The bridge switch circuit transforms the output signal of the PFC circuit into a pulse signal. The resonant circuit resonates and outputs a sinusoidal signal to a primary-side of the transformer based on the pulse signal. The feedback circuit outputs the feedback signal to the PFC circuit in response to a primary-side current of the transformer. Therefore, an output current of the LED driving device is adjusted through modulating the feedback circuit. | 06-11-2009 |
20090271135 | Detecting Device for Detecting an Operating Mode of a System and Detecting Method Thereof - A detecting device for detecting an operating mode is disclosed. The detecting device includes a pulse generator and a hold-up unit. The pulse generator is disposed for issuing a one-shot pulse signal in response to each of button signals respectively. The hold-up unit is disposed for receiving the button signals to respectively generate delayed button signals by way of clock delay determined by a clock signal. The one-shot pulse signal and the delayed button signals are used to determine an operating mode of a system. | 10-29-2009 |
20100124084 | POWER CONVERTER WITH CONTROL CIRCUIT AND RELATED CONTROL METHOD - A control circuit for use in a power converter has a multi-function terminal, a current comparator circuit, and an under-voltage detection circuit. The current comparator circuit compares current flowing through a power switch of the power converter with a reference value through the multi-function terminal when the power switch is on, and turns the power switch off when the current reaches the reference value. The under-voltage detection circuit determines whether an input voltage of the power converter is less than a predetermined value through the multi-function terminal when the power switch is turned off. | 05-20-2010 |
20110032024 | Integrated Circuit and Related Method for Determining Operation Modes - An integrated circuit and a related method for determining an operation mode are disclosed. The exemplified integrated circuit includes a controller, a multi-function pin, and a mode determination circuit. The controller controls a power switch and is being set to operate in one of the operation modes including a first operation mode and a second operation mode. The multi-function pin is connected to an external resistor. The mode determination circuit detects a signal from the multi-function pin. The signal represents the resistance of the external resistor. If the resistance is within a first range, the controller is operated in the first operation mode. If the resistance is within a second range, the controller is operated in the second operation mode. | 02-10-2011 |
20110133714 | POWER CONVERTER WITH PROTECTION MECHANISM FOR DIODE IN OPEN-CIRCUIT CONDITION AND PULSE-WIDTH-MODULATION CONTROLLER THEREOF - A power converter with a protection mechanism for a diode in an open-circuit condition includes a DC to Dc (DC/DC) conversion circuit, a detection and protection circuit, a pulse-width-modulation (PWM) signal generator, and a logic gate. The detection and protection circuit is used for detecting an open-circuit condition of the diode of the DC/DC conversion circuit. The logic gate receives an output signal of the detection and protection circuit and a PWM signal outputted by the PWM signal generator. When the diode is in an open-circuit condition, the PWM signal cannot be transmitted to a power switch of the DC/DC conversion circuit due to the output signal of the detection and protection circuit. | 06-09-2011 |
20120074917 | Adaptive slope-compensation module and method thereof - An adaptive slope-compensation method is applied for a switch-mode power supply. The switch-mode power supply has a power switch, and an inductor coupled to an input power. The power switch controls the inductor storing energy or releasing energy to generate an output voltage. The adaptive slope-compensation method includes detecting an inductor current passing through the inductor and to generate an inductor-current detecting voltage, detecting a duty cycle of the power switch, detecting a voltage variation of the inductor-current detecting voltage when the power switch is turned on, generating a slope-compensation signal according to the voltage variation and the duty cycle, and adjusting the timing of turning the power switch on or off. In this way, even if the operation conditions of the input power and the output voltage change, the system still can quickly response and does not generate sub-harmonic oscillation. | 03-29-2012 |
20120159207 | POWER MANAGEMENT DEVICE AND METHOD THEREOF - A power management device of an SD memory card reader includes a power supply regulator and a controller. The controller controls the power supply regulator to provide a memory card voltage according to an external control signal transmitted from a single control pin. Wherein when the external control signal denotes an enable state, the power supply regulator provides the memory card voltage; when the external control signal denotes a disable state, the power supply regulator stops providing the memory card voltage and discharges the load capacitor; and when the external control signal returns to the enable state from the disable state in a predetermined duration, the power supply regulator changes the memory card voltage. | 06-21-2012 |
20130301302 | POWER SUPPLY AND POWER CONTROLLER - Power supplies and power controllers are disclosed. A disclosed power supply has a power controller, a power switch, an auxiliary winding, a first circuit and a second circuit. The power controller is a monolithic integrated circuit with a multi-function pin and a gate pin. A control node of the power switch is coupled to the gate pin. The first circuit is coupled between the multi-function pin and the auxiliary winding and has a diode. The second circuit is coupled between the multi-function pin and a ground line, and has a thermistor. | 11-14-2013 |