Abstract: A DC-DC converter operates outside of an audible frequency range under light current load conditions with reduced switching frequency by reducing supply current and regulating output voltage. A control for the converter maintains the switching frequency above an audible frequency range and reduces supply current by modulating switch on-time, sinking supply current, or permitting negative supply current values. The output voltage of the converter is regulated by modulating switch on-time, clamping output voltage, or modifying feedback detector thresholds. The power converter operates with improved efficiency under light current load conditions, while avoiding operation in an audible frequency range to prevent the generation of audible noise in converter components.

Abstract: A controller for a DC/DC converter is provided. The controller comprises an error circuit, control logic, a high side driver, a low side driver, and an interface circuit. The error circuit is coupled to a feedback terminal so as to receives a feedback signal and is coupled to the control logic. The high side driver is coupled to the control logic and to a first output terminal so as to provide a first actuation signal, and the low side driver is coupled to the control logic and to a second output terminal so as to provide a second actuation signal. The interface circuit is also coupled to the control logic, including a first, second, and third voltage source, interface comparators, and current limited amplifier.

Abstract: In one embodiment, a switching regulator comprises a control circuit that activates and deactivates at least one power switch to control a voltage of a switching node. The system also comprises an inductor that conducts a current from the switching node to an output to generate an output voltage. The system further comprises a PWM comparison circuit that controls an on-time and/or an off-time of the at least one power switch based on a comparison of a feedback voltage and a reference voltage. The PWM comparison circuit comprises a ramp signal generator configured to provide a ramp signal having a non-zero slope that is combined with either the feedback voltage or the reference voltage at a beginning of either the on-time or the off-time. The PWM comparison circuit can be further configured to set the slope of the ramp signal to zero during the off-time in a discontinuous conduction mode.

Abstract: A converter for a multi-phase current network can include a plurality of current sensors, each of the plurality of current sensors being configured to detect current for a respective phase of the multi-phase network. A current averaging circuit is configured to provide an indication of the average current for the multi-phase network based on the current detected by each of the plurality of current sensors. A modulator is configured to modulate at least one phase of the multi-phase network independently of each other phase of the multi-phase network based on a difference between the current detected for the at least one phase and the average current for the multi-phase network.

Abstract: Various apparatuses, methods and systems for a DC to DC converter with a pseudo constant switching frequency are disclosed herein. For example, some embodiments provide a DC to DC converter having a switch connected to a switching node to control a voltage of the switching node, and a switching controller that is adapted to turn on and off the switch at a substantially constant frequency based at least in part on the voltage of the switching node. The switching controller includes a modulator connected to a control electrode of the switch and that is adapted to actuate and deactuate the switch, and a first timer that is connected to the switching node and to the modulator. The first timer uses the voltage of the switching node to determine an on-time for the switch.

Abstract: An adjustable compensation offset voltage is applied to a comparator to vary turn-off timing of a synchronous rectifier. A comparator output indicates when current through an inductor coupled to the synchronous rectifier should be approaching zero. If the synchronous rectifier is turned off before the current through the inductor reaches zero, the compensation offset voltage is adjusted to delay the synchronous rectifier turn-off for the next switching cycle. If the synchronous rectifier is turned off after the current through the inductor reaches zero, the compensation offset voltage is adjusted to advance the synchronous rectifier turn-off for the next switching cycle. An up/down counter, in conjunction with a digital to analog converter, may be used to provide the adjustment to the compensation offset voltage. The adjustable compensation offset voltage improves the accuracy of synchronous rectifier turn-off in relation to a zero inductor current, thereby improving power converter efficiency.

Abstract: In one embodiment, a switching regulator comprises a control circuit that activates and deactivates at least one power switch to control a voltage of a switching node. The system also comprises an inductor that conducts a current from the switching node to an output to generate an output voltage. The system further comprises a PWM comparison circuit that controls an on-time and/or an off-time of the at least one power switch based on a comparison of a feedback voltage and a reference voltage. The PWM comparison circuit comprises a ramp signal generator configured to provide a ramp signal having a non-zero slope that is combined with either the feedback voltage or the reference voltage at a beginning of either the on-time or the off-time. The PWM comparison circuit can be further configured to set the slope of the ramp signal to zero during the off-time in a discontinuous conduction mode.

Abstract: A DC-DC converter operates outside of an audible frequency range under light current load conditions with reduced switching frequency by reducing supply current and regulating output voltage. A control for the converter maintains the switching frequency above an audible frequency range and reduces supply current by modulating switch on-time, sinking supply current, or permitting negative supply current values. The output voltage of the converter is regulated by modulating switch on-time, clamping output voltage, or modifying feedback detector thresholds. The power converter operates with improved efficiency under light current load conditions, while avoiding operation in an audible frequency range to prevent the generation of audible noise in converter components.

Abstract: The objective of this invention is to provide a pulse signal generator with a simple constitution that can reduce the number of signals required for setting the pulse width, as well as a display device using said pulse signal generator. Pulse assignment signal DP0 input to the initial stage of pulse signal generating units PG(i,0)–PG(i,39) connected in cascade is sequentially transferred towards the last stage of the cascade connection. After transfer of the pulse assignment signal to the pulse signal generating unit in each stage, the count value of said pulse signal generating unit is initialized. Then, the pulses of pulse strings PS0–PS39 in the various pulse signal generating units are counted. The count value of the pulse string is compared to the pulse assignment signal in the comparison unit of each pulse signal generating unit, and, in accordance with the comparison result, the level of the drive pulse signal of the LED is inverted.

Abstract: A charge pump DC/DC converter having an improved the ripple characteristic in its output voltage and make it possible to adjust the boosting rate in a stepwise manner. In phase I, two flying capacitors Ca, Cb are connected in series between voltage input terminal 12 and voltage output terminal 14. In this connection state, flying capacitor Ca is charged by the current supplied from DC power supply 10, while flying capacitor Cb discharges to the load side. In phase II, flying capacitor Ca is connected between voltage input terminal 12 and voltage output terminal 14, while flying capacitor Cb is connected between voltage input terminal 12 and the ground potential. In this connection state, flying capacitor Ca discharges to the load side, while flying capacitor Cb is charged by the current supplied from DC power supply 10.

Abstract: A DC—DC converter can supply a stable output voltage from an input voltage with the power supply voltage varying along with the supply of the power and can maintain a high voltage conversion efficiency. The DC—DC converter includes an inductive element and the first-fourth switches connected to both terminals of the inductive element, the first and second switches are turned on and off periodically corresponding to the input voltage. When the input voltage goes below a prescribed reference level, a first control signal that keeps the first switch constantly on is generated by a feedforward control circuit to turn on the third and fourth switches periodically corresponding to the output voltage so that the output time of the third switch is generated by a feedback control circuit to switch the voltage increasing operation and the voltage increasing/decreasing operation corresponding to the input voltage.

Abstract: A pulse width modulation (PWM) controller includes a shutter circuit interposed between a PWM modulator and a driver circuit. The shutter circuit receives a raw PWM output signal from the PWM modulator and processes the raw PWM signal to eliminate double pulsing that may be present on the raw PWM signal. Bypass logic responsive to a switch or software controlled enable input is provided to permit the shutter circuit to be included in the PWM controller or alternatively, to be bypassed.

Abstract: A pulse width modulation (PWM) controller includes a shutter circuit interposed between a PWM modulator and a driver circuit. The shutter circuit receives a raw PWM output signal from the PWM modulator and processes the raw PWM signal to eliminate double pulsing that may be present on the raw PWM signal. Bypass logic responsive to a switch or software controlled enable input is provided to permit the shutter circuit to be included in the PWM controller or alternatively, to be bypassed.

Abstract: The objective of this invention is to provide a pulse signal generator with a simple constitution that can reduce the number of signals required for setting the pulse width, as well as a display device using said pulse signal generator. Pulse assignment signal DP0 input to the initial stage of pulse signal generating units PG(i,0)-PG(i,39) connected in cascade is sequentially transferred towards the last stage of the cascade connection. After transfer of the pulse assignment signal to the pulse signal generating unit in each stage, the count value of said pulse signal generating unit is initialized. Then, the pulses of pulse strings PS0-PS39 in the various pulse signal generating units are counted. The count value of the pulse string is compared to the pulse assignment signal in the comparison unit of each pulse signal generating unit, and, in accordance with the comparison result, the level of the drive pulse signal of the LED is inverted.

Abstract: A charge pump DC/DC converter having an improved the ripple characteristic in its output voltage and make it possible to adjust the boosting rate in a stepwise manner. In phase I, two flying capacitors Ca, Cb are connected in series between voltage input terminal 12 and voltage output terminal 14. In this connection state, flying capacitor Ca is charged by the current supplied from DC power supply 10, while flying capacitor Cb discharges to the load side. In phase II, flying capacitor Ca is connected between voltage input terminal 12 and voltage output terminal 14, while flying capacitor Cb is connected between voltage input terminal 12 and the ground potential. In this connection state, flying capacitor Ca discharges to the load side, while flying capacitor Cb is charged by the current supplied from DC power supply 10.

Abstract: A DC—DC converter prevents reverse current from flowing through the inductor, suppresses ringing noise in the low-load state, lowers the power consumption, and increases the conversion efficiency. In the DC—DC converter composed of switches S1-S4 and inductor L1, in switching controller 10, output voltage Vout and current IL in inductor L1 are detected, and in accordance with the detection result, switches S1-S4 are turned on/off so that output voltage Vout is held at desired level; also, when the current in inductor L1 is nearly zero, switches S2 and S3 are turned on, and switch S4 on the output side of inductor L1 is turned off, so that reverse current flow through the inductor can be prevented, and the generation of ringing noise can be suppressed.

Abstract: A DC-DC converter prevents reverse current from flowing through the inductor, suppresses ringing noise in the low-load state, lowers the power consumption, and increases the conversion efficiency. In the DC-DC converter composed of switches S1-S4 and inductor L1, in switching controller 10, output voltage Vout and current IL in inductor L1 are detected, and in accordance with the detection result, switches S1-S4 are turned on/off so that output voltage Vout is held at the desired level; also, when the current in inductor L1 is nearly zero, switches S2 and S3 are turned on, and switch S4 on the output side of inductor L1 is turned off, so that reverse current flow through the inductor can be prevented, and the generation of ringing noise can be suppressed.

Abstract: A DC-DC converter that does not need a series resistance element on the output side, and can make use of the parasitic resistance of a coil to improve output characteristics and prevent a decrease in efficiency. In switching unit 40, transistors M1 and M2 are turned ON/OFF alternately in correspondence with pulse signal Sp; input voltage Vin is fed intermittently to node ND1; in output filter unit 10, output voltage Vout that is smoothed with coil Le and capacitor Cout is output to terminal Tout. In feedback control unit 100, divided voltage Vo1 obtained by dividing the voltage at node ND1 is compared with reference voltage Vref, and the result of the comparison is integrated to generate control voltage Vc. In PWM modulation unit 30, pulse signal Sp with pulse width controlled is generated according to control voltage Vc and sent to switching unit 40.

Abstract: A DC-DC converter that does not need a series resistance element on the output side, and can make use of the parasitic resistance of a coil to improve output characteristics and prevent a decrease in efficiency. In switching unit 40, transistors M1 and M2 are turned ON/OFF alternately in correspondence with pulse signal Sp; input voltage Vin is fed intermittently to node ND1; in output filter unit 10, output voltage Vout that is smoothed with coil Le and capacitor Cout is output to terminal Tout. In feedback control unit 100, divided voltage Vo1 obtained by dividing the voltage at node ND1 is compared with reference voltage Vref, and the result of the comparison is integrated to generate control voltage Vc. In PWM modulation unit 30, pulse signal Sp with pulse width controlled is generated according to control voltage Vc and sent to switching unit 40.

Abstract: An RC series circuit is provided in parallel with an inductor. The RC series circuit is comprised of a resistor and a capacitor which are connected with each other in series. A voltage across the capacitor is applied to a detection circuit. The detection circuit detects inductor current flowing through the inductor based on the applied voltage. If the inductance of the inductor, the parasitic resistance value of the inductor, the capacitance of the capacitor and the resistance value of the resistor are L, RL, Ca and Ra, respectively, the RC series circuit is designed so as to satisfy L/RL=Ca*Ra.