Abstract: A PWM controller for controlling a switching voltage regulator comprises a first comparator, a second comparator and a third comparator. The first comparator is configured to detect voltages of a first node and a second node so as to determine whether to stop the PWM controller. The PWM controller is stopped if a first potential is lower than a threshold, and the first potential derives from the voltage of the first node by a level shift of a first voltage difference. The second comparator is configured to detect the voltage of the first node and then to compare the voltage with a power reference voltage so as to determine whether the PWM controller receives necessary power. The third comparator is configured to compare the voltage of the second node with an enable reference voltage so as to determine whether to disable the PWN controller.

Abstract: A pulse width modulation controller comprises a disabling unit, a level sensor and an over current protector. These three devices are all coupled to a multi-function node for accomplishing a disable function, input level sensing, and over-current protection, respectively.

Abstract: A PWM controller for controlling a switching voltage regulator comprises a first comparator, a second comparator and a third comparator. The first comparator is configured to detect voltages of a first node and a second node so as to determine whether to stop the PWM controller. The PWM controller is stopped if a first potential is lower than a threshold, and the first potential derives from the voltage of the first node by a level shift of a first voltage difference. The second comparator is configured to detect the voltage of the first node and then to compare the voltage with a power reference voltage so as to determine whether the PWM controller receives necessary power. The third comparator is configured to compare the voltage of the second node with an enable reference voltage so as to determine whether to disable the PWN controller.

Abstract: A PWM controller applied to a switching voltage regulator comprises a disabling circuit, a power-sensing circuit, an over-current protection circuit and a PWM logic circuit. The disabling circuit is connected to an external frequency compensation circuit for detecting a voltage used to stop the operation of the PWM controller. The power-sensing circuit is configured to stop the operation of the PWM controller if the input voltage of the high side switch is lower than a threshold. The over-current protection circuit is configured to monitor current flowing through the output circuit, and the over-current protection circuit generates an over-current protection signal when the current exceeds a threshold. The PWM logic circuit is connected to the outputs of the disabling circuit, power-sensing circuit and over-current protection circuit.

Abstract: A spring modulation is proposed to regulate the output voltage of a voltage regulator. The spring modulation comprises a differential amplifier to generate a pair of voltage signal and current signal varied with the difference between a reference signal and a feedback signal related to the output voltage, and a PWM generator to generate a PWM signal in response to the pair of voltage signal and current signal to regulate the output voltage, in such a manner that, in load transient, the greater the difference between the feedback signal and reference signal is, the greater the on-time duty-cycle of the PWM signal is.

Abstract: A DC-to-DC converter comprises a sense circuit to sense the output voltage of the converter to generate a feedback signal, a transconductive amplifier to amplify a difference between the feedback signal and a threshold signal to generate a first current and to generate a second current in response to a load transient, a charging circuit connected with the first current to generate a charging voltage, a driver to compare the charging voltage with two reference signals to generate a pair of low-side and high-side driving signals, and a fast response circuit to compare a load transient signal corresponding to the second current with a third reference signal to generate a bypass signal to drive the output stage of the converter in the load transient.

Abstract: A fixed-frequency current mode converter comprises a power stage to produce an inductor current and an output voltage, an error amplifier to generate an error signal from the difference between the output voltage and a reference voltage varied with the inductor current, a comparator to compare the error signal with a ramp signal varied with the inductor current to generate a comparison signal, and a PWM generator to generate a PWM signal in response to a fixed-frequency clock and the comparison signal to drive the power stage. A second comparator is further comprised to compare the error signal with a second reference voltage varied with the inductor current, and generates a second comparison signal to reset the clock when the error signal is lower than the second reference voltage.

Abstract: In a noise sensitivity improved switching system and method thereof, comprised sensing the output voltage of the switching system to generate a feedback signal, respectively amplifying the feedback signal by two gains to generate two signals in phase or out of phase, filtering one of the two amplified signals, and summing or comparing the filtered signal and the other one, thereby reducing the noise interference to the switching system.

Abstract: A spring modulation is proposed to regulate the output voltage of a voltage regulator. The spring modulation comprises a differential amplifier to generate a pair of voltage signal and current signal varied with the difference between a reference signal and a feedback signal related to the output voltage, and a PWM generator to generate a PWM signal in response to the pair of voltage signal and current signal to regulate the output voltage, in such a manner that, in load transient, the greater the difference between the feedback signal and reference signal is, the greater the on-time duty-cycle of the PWM signal is.

Abstract: A fixed-frequency current mode converter comprises a power stage to produce an inductor current and an output voltage, an error amplifier to generate an error signal from the difference between the output voltage and a reference voltage varied with the inductor current, a comparator to compare the error signal with a ramp signal varied with the inductor current to generate a comparison signal, and a PWM generator to generate a PWM signal in response to a fixed-frequency clock and the comparison signal to drive the power stage. A second comparator is further comprised to compare the error signal with a second reference voltage varied with the inductor current, and generates a second comparison signal to reset the clock when the error signal is lower than the second reference voltage.

Abstract: A delta-sigma DC-to-DC converter comprises a pair of high-side and low-side switches switched to convert an input voltage to an output voltage, a sense circuit to sense the output voltage of the converter to generate a feedback signal, a transconductive amplifier to amplify a difference between the feedback signal and a threshold signal to generate a differential current, a charging circuit connected with the differential current to generate a charging voltage, and a driver to compare the charging voltage with two reference signals to generate the pair of low-side and high-side driving signals.

Abstract: In a noise sensitivity improved switching system and method thereof, comprised sensing the output voltage of the switching system to generate a feedback signal, respectively amplifying the feedback signal by two gains to generate two signals in phase or out of phase, filtering one of the two amplified signals, and summing or comparing the filtered signal and the other one, thereby reducing the noise interference to the switching system.

Abstract: A switching regulator with improved load transient efficiency comprises an output stage to generate an output voltage, a pulse width modulation circuit to generate a pulse width modulation signal, a constant ON-time circuit to generate an ON-time signal in accordance with the pulse width modulation signal to drive the output stage, and a masking apparatus to mask the ON-time signal by the pulse width modulation signal to thereby drive the output stage during load transient. During load transient, the masking apparatus reduces the switching times of the output stage to thereby reduce the switching loss and thus improve the efficiency of the regulator.

Abstract: A DC-to-DC converter comprises a sense circuit to sense the output voltage of the converter to generate a feedback signal, a transconductive amplifier to amplify a difference between the feedback signal and a threshold signal to generate a first current and to generate a second current in response to a load transient, a charging circuit connected with the first current to generate a charging voltage, a driver to compare the charging voltage with two reference signals to generate a pair of low-side and high-side driving signals, and a fast response circuit to compare a load transient signal corresponding to the second current with a third reference signal to generate a bypass signal to drive the output stage of the converter in the load transient.

Abstract: A delta-sigma DC-to-DC converter comprises a pair of high-side and low-side switches switched to convert an input voltage to an output voltage, a sense circuit to sense the output voltage of the converter to generate a feedback signal, a transconductive amplifier to amplify a difference between the feedback signal and a threshold signal to generate a differential current, a charging circuit connected with the differential current to generate a charging voltage, and a driver to compare the charging voltage with two reference signals to generate the pair of low-side and high-side driving signals.

Abstract: A jig for testing the printed circuit boards utilizes the adjustable guide members to easily position different sizes of circuit boards on a working plate, wherein the working plate can smoothly slide up and down along the guide columns and the elastic members without jamming. The second surface of the working plate is formed with a concavity and several bulged sections to stably place the circuit board without deformation, and therefore the soldering points of the circuit board can uniformly touch the tips of the probes which are retractably installed in the through holes of the base. By using the assembling base, the maintenance of the internal structure of the base can be improved.