Patent application number | Description | Published |
20080231244 | DC-DC CONVERTER - An overcurrent detection circuit ( | 09-25-2008 |
20080247198 | CONTROL CIRCUIT AND CONTROLLING METHOD OF SWITCHING POWER SUPPLY SYSTEM - A switching power supply system has a control circuit that controls an output voltage by causing a switching device to turn ON and OFF. The control circuit includes a control pulse supplying unit that supplies a pulsed signal that_keeps the switching device turned-ON and -OFF. A protection circuit shuts down the switching power supply system upon occurrence of an abnormality. A delay circuit produces a delay signal that delays by a specified time duration the termination of a state of the pulsed signal in which the pulsed signal keeps the switching device turned-ON. The protection circuit is responsive to the pulsed signal or the delay signal to switch between an operation state and a stand-by state. | 10-09-2008 |
20090096436 | DC-DC CONVERTER - A DC-DC converter includes a series circuit of a main switch and a choke coil and an output capacitor connected to one end of the series circuit and outputs a DC voltage from the one end of the series circuit. A first MOS transistor is connected in parallel to the series circuit and a second MOS transistor is connected in parallel to the output capacitor. A control circuit controls the gate voltages of the first MOS transistor and/or the second MOS transistor so that the first MOS transistor and/or the second MOS transistor outputs a changed target output voltage, whereby the output voltage is made equal to the target voltage at high speed. | 04-16-2009 |
20110298497 | COMPARATOR CIRCUIT - A comparator circuit can achieve a reduction in current consumption with a simple configuration, and can suppress an increase in current consumption accompanying a rise in power source voltage. A current mirror circuit is connected to a power source, and gates of MOSFETs of the circuit are interconnected. An input signal is applied to a gate of an NMOSFET of the circuit. By determining the value of the signal with a constant voltage device, the voltage across a tail resistor is constant, even in the event that the power source voltage and the input signal change. | 12-08-2011 |
20120212205 | CONTROL SYSTEM OF DC TO DC CONVERTER - A control system of a DC to DC converter skips switching pulses according to the output of an overvoltage protection circuit. The overvoltage protection circuit includes an overvoltage threshold voltage control section that lowers an overvoltage threshold voltage when the pulse width has a minimum valve. The control system both improves the output voltage accuracy of the DC to DC converter under a light load and promotes a quick return to normal operation after an overvoltage protection operation under a heavy load. | 08-23-2012 |
20120223690 | DC-DC CONVERTER CONTROL CIRCUIT AND CONTROL METHOD - A control circuit of a DC-DC converter that has a switching element, including an error amplifier that amplifies a difference between a reference voltage and a feedback voltage corresponding to an output voltage of the DC-DC converter, a voltage reduction comparator that outputs an interrupt signal when the feedback voltage is lower than a voltage reduction threshold that has a value lower than that of the reference voltage, and a pulse-width modulation (PWM) signal generator circuit. The PWM signal generator circuit generates a PWM signal of a predetermined frequency based on the voltage difference when no interrupt signal is generated, or otherwise generates a switch drive signal to activate the switching element for a first period of time corresponding to the difference output by the error amplifier, and to deactivate the switching element for a second period of time after the first period of time has elapsed. | 09-06-2012 |
20120268093 | DC-DC CONVERTER CONTROL METHOD AND DC-DC CONVERTER CONTROL CIRCUIT - The transient response of an output voltage to a load fluctuation is improved, in a switching power source that carries out a PWM control. In a DC-DC converter wherein a switching element of an output stage is controlled by a drive signal, whose pulse width is set at a minimum value, output from a PWM signal generating circuit based on an output voltage output from an error amplifier in accordance with the difference between a feedback voltage in accordance with an output voltage of the output stage and a reference voltage, there is provided a minimum pulse width detector circuit that supplies a current to a phase compensation capacitor when the pulse width of the drive signal is at the minimum value, thus preventing the output voltage from dropping below a value corresponding to the minimum value when the load fluctuates, and improving transient response characteristics of the output voltage. | 10-25-2012 |
20120286827 | VOLTAGE-TO-CURRENT CONVERTER CIRCUIT - A voltage-to-current converter circuit has a differential input unit, and is provided with an input offset voltage, wherein the temperature characteristics of the differential input unit and input offset voltage are substantially flat. A current is supplied wherein a second fixed current having positive temperature characteristics is added to a first fixed current having flat characteristics as a bias current to the differential input unit, to balance the temperature characteristics of the differential input unit and the temperature characteristics of the bias current, thus causing the differential input unit transconductance temperature characteristics to be substantially zero (e.g., substantially flat). | 11-15-2012 |
20130241512 | STEP-UP SWITCHING POWER SUPPLY - A hysteresis control step-up switching power supply includes a switching element. Current flowing through the switching element does not continue to increase indefinitely. The switching element is turned off when a detected value of an output voltage increases to a reference voltage, or when the output of a current detector circuit that detects that a current flowing through the switching element increases to a reference current value. | 09-19-2013 |
20140347034 | AC INPUT VOLTAGE INTERRUPTION DETECTION METHOD AND CIRCUIT - A selector circuit selects either a class upper-limit voltage or a class lower-limit voltage as a reference voltage of a comparator. A control logic controls the selector circuit, and generates a count-up signal or a count-down signal in accordance with the output of the comparator. An up/down counter counts up upon reception of the count-up signal from the control logic, and counts down upon reception of the count-down signal. A digital-analog converter outputs the class upper-limit voltage and the class lower-limit voltage in accordance with a digital value that is outputted by the up/down counter. A timer circuit is configured to be reset by the count-up signal from the control logic to the up/down counter. | 11-27-2014 |