Patent application number | Description | Published |
20100019682 | LED driver and controller thereof - A LED driver is disclosed for providing a current for LED lighting. The LED driver includes an inductor and a controller having a power switch, and the inductor, the power switch and a LED to be driven are configured to be an asynchronous boost converter. Because the driven LED serves as a rectifier diode of the asynchronous boost converter, the controller may have fewer components and requires smaller die area. | 01-28-2010 |
20100066312 | Overvoltage protection circuit for use in charger circuit system and charge circuit with overvoltage protection function - The present invention discloses an overvoltage protection (OVP) circuit for use in a charger circuit system, comprising: a power transistor electrically connected between a voltage supply and a battery; an OVP circuit which turns off the transistor when a voltage supply exceeds a threshold value; and a multiplexing circuit electrically connected between an output of the OVP circuit and the gate of the transistor. The present invention also discloses a charger circuit with an OVP function, comprising: a single power transistor electrically connected between a voltage supply and a battery; an OVP control circuit which turns off the power transistor when a voltage supply exceeds a threshold value; and a charger control circuit which controls the gate of the power transistor to determine a charge current to the battery when the voltage supply does not reach the threshold value. | 03-18-2010 |
20100072915 | Boost driver circuit with fast discharging function - The present invention discloses a boost driver circuit which converts an input voltage to an output voltage and supplies it to a load, the boost driver circuit comprising: a power transistor electrically connected with a node between the input voltage and the output voltage; a pulse width modulation driver circuit for controlling the operation of the power transistor; an output node electrically connected with the output voltage; a feedback node electrically connected with the load; a low voltage transistor electrically connected with the feedback node; and a clamp and fast discharge circuit electrically connected with the feedback node for discharging the feedback node when the voltage at the feedback node is higher than a predetermined voltage. | 03-25-2010 |
20110001461 | Buck-boost switching regulator and control circuit and method therefor - The present invention discloses a buck-boost switching regulator, and a control circuit and a method therefor, to convert an input voltage to an output voltage. The control method comprises: obtaining a feedback signal relating to the output voltage; comparing the feedback signal with a reference voltage to generate an error amplified signal; when the error amplified signal is between a first voltage (V | 01-06-2011 |
20130181776 | RAIL-TO-RAIL COMPARATOR - The present invention discloses a rail-to-rail comparator. The rail-to-rail comparator includes: a positive voltage rail providing a positive supply voltage, a ground voltage rail providing a ground voltage, an input stage, and an output stage. The input stage includes: a positive and a negative input terminals for receiving a first input signal and a second input signal; a first differential amplifier circuit, which includes a pair of depletion NMOS transistors to generate a first pair of differential currents; and a second differential amplifier circuit, which includes a pair of native NMOS transistors to generate a second pair of differential currents. The output stage is coupled to the first differential amplifier circuit and the second differential amplifier circuit, and generates an output signal related to a difference between the first input signal and the second input signal. | 07-18-2013 |
20130293204 | CONTROL CIRCUIT FOR REDUCING SWITCHING LOSS OF BUCK-BOOST CONVERTER AND RELATED SWITCHING REGULATOR - The switching regulator of a buck-boost converter includes a first, a second, a third, and a fourth switches. A control circuit for controlling the switching regulator includes an error detector, a ramp signal generator, a comparator, an oscillator, and a control signal generator. The error detector generates an error signal corresponding to an output voltage of the switching regulator. The ramp signal generator generates a ramp signal. The comparator compares the error signal and the ramp signal to generate a comparison signal. The oscillator generates an oscillating signal. The control signal generator controls the first, the second, the third, and the fourth switches according to the comparison signal, the oscillating signal, and a clock signal, so that the switching regulator is configured to switch only between a boost mode and a buck mode, and not to operate at a buck-boost mode. | 11-07-2013 |
20140062435 | CHARGING CONTROL CIRCUIT - The present invention discloses a charge control circuit for supplying power from an external power source to a first common node and charging a second common node from the first common node. A regulator circuit is coupled between the external power source and the first common node, and a transistor is coupled between the first common node and the second common node. The present invention detects an operation parameter of the transistor and controls an internal voltage source to generate a non-predetermined voltage difference accordingly. When the sum of the voltage at the second common node and the non-predetermined voltage is equal to or higher than the reference voltage, the voltage at the first common node is regulated to a level higher than the voltage at the second common node, and the transistor is in an optimum conductive state. | 03-06-2014 |
20140266133 | POWER CONVERTING CIRCUIT AND CONTROL CIRCUIT THEREOF - A power converting circuit includes an upper gate switch, a transistor, a current source circuit, a comparator circuit, a delay circuit, and a pulse width modulation signal generating circuit. The transistor and the current source circuit provide a reference signal. The comparator circuit generates a comparing signal according to the reference signal and an output signal provided by the upper gate switch. The delay circuit generates a delay signal according to the comparing signal and a clock signal. The pulse width modulation signal generating circuit generates a control signal for the upper gate switch according to the delay signal and the clock signal for configuring the conduction status of the upper gate switch. The power converting circuit adjusts the conduction time of the upper gate switch according to the reference signal and the output signal. | 09-18-2014 |