Abstract: A switch mode power supply (SMPS) with control scheme selection for high-voltage configuration and low-voltage configuration of the SMPS. The SMPS operates in at least a charge state or a release state. The SMPS has a mode control module receiving a mode setting signal indicative of the configuration of the SMPS and a state indication signal indicative of the state of the SMPS. The SMPS selects a boost control module or a buck control module to control the SMPS according to the mode setting signal and the state indication signal.

Abstract: A current limit peak regulation circuit, a current limit circuit and a power converter including the current limit peak regulation circuit. The current limit peak regulation circuit provides a current limit threshold to limit a maximum allowable peak current value of a current flowing through a main switch of the power converter and adjusts the current limit threshold to decrease with decrease in a switching frequency of the power converter when the power converter is in a constant voltage mode so as to reduce power dissipation of the power converter in standby mode.

Abstract: Switching mode power supply (SMPS) having a switch circuit and a controller. The switch circuit has an output inductor and a switch with a minimum on time. A control signal is generated by the controller to control the switching operation of the switch based on a clock signal with a switching frequency and an off signal. When the required on time of the switch is smaller than the minimum on time, the SMPS reduces the switching frequency adaptively and the actual on time of the switch is controlled to be the minimum on time.

Abstract: A method for forming a steeped oxide on a substrate is described: successively forming a first pad oxide layer, a nitride layer, a second pad oxide layer and a poly layer on the substrate; etching the poly layer to have an opening for the stepped oxide region; isotropically etching the second pad oxide layer to the nitride layer through the opening to form a stepped trench; isotropically etching the nitride layer to the first pad oxide layer through the opening to expand the stepped trench; filling the stepped trench with dielectric material to form a dielectric layer; planarizing the dielectric layer; removing the poly layer; removing the second pad oxide layer; removing the nitride layer; removing the portion of the first pad oxide layer uncovered by the dielectric layer such that the remaining first pad oxide layer together the remaining dielectric layer forms the stepped oxide.

Abstract: A buck-boost converter automatically chooses work mode between buck mode, boost mode and buck-boost mode, in response to an input voltage and an output voltage. The buck-boost converter is with simple structure, convenient mode transition and lower output voltage ripple.

Abstract: A magnetic angular sensing system has a magnet magnetized radially and a magnetic angular sensor for sensing the angular position of the magnet. The magnetic angular sensor is mounted in parallel to the axis of the magnet and is non-coplanar with the magnet. The magnetic angular sensor senses an angular position of the magnet based on a detected axial magnetic field component and a tangential magnetic field component of the magnetic field vector where the sensor mounted. This invention provides a flexible sensing system.

Abstract: A method for fabricating a semiconductor device including: forming a block layer above a well region of a first doping type in a semiconductor substrate, wherein the block layer has an opening for defining a first region in an upper part of the well region and has sidewalls at sides of the opening; implanting dopants of a second doping type into the well region through the opening of the block layer to form the first region; implanting dopants of the first doping type into the first region in the manner of large-angle-tilt dopants implantation to form a second region for a first transistor, and to form a third region for a second transistor; and forming, for both of the first transistor and the second transistor, a fourth region between the second region and the third region.

Abstract: A bidirectional current sensing circuit includes: a sensing resistor coupled between a load and a reference ground, a first and second auto-zero amplifiers coupled to the sensing resistor to sense the voltage across the sensing resistor, and an output transistor. One of the first and second auto-zero amplifiers operates in an output mode and the other of the first and second auto-zero amplifiers operates in a zeroing mode according to a polarity of a voltage across the sensing resistor. The output transistor has a first terminal providing a current sensing signal indicating a load current, a second terminal electrically connected to an inverting terminal of the one of the first and second auto-zero amplifiers operating in the output mode, and a control terminal electrically connected to an output terminal of the one of the first and second auto-zero amplifiers operating in the output mode.

Abstract: A multi-rail switching converter providing a plurality of output voltages has a master switching circuit, a plurality of slave switching circuits and a control circuit. The control circuit has an interleaving control circuit, the interleaving control circuit judges a phase zone of a corresponding slave switching circuit based on a switching control signal of the master switching circuit and a set signal of the corresponding slave switching circuit, and adjusts a turn-ON moment of the corresponding slave switching circuit based on the phase zone of the corresponding slave switching circuit.

Abstract: A LED driver adopts one power stage to provide a constant drive current to drive a load, and to provide different power supply voltages to power a smart module according to a dimming signal input by users through the smart module. The LED driver provides high performance with simple circuit structure.

Abstract: An AC switch circuit coupled between an AC input signal and an AC load has a first switch, a second switch, a driving circuit, and a power generation circuit. The first switch blocks a first half-cycle of the AC input signal when turned OFF, and the second switch blocks a second half-cycle of the AC input signal when turned OFF. The driving circuit provides a driving signal to control the first switch and the second switch based on an enable signal. The power generation circuit provides a voltage signal to power the driving circuit. The power generation circuit stores energy from the AC input signal when the first switch and the second switch are turned OFF, and the power generation circuit is disconnected from the AC input signal when the first switch and the second switch are turned ON.

Abstract: A method for fabricating a LDMOS device in a well region of a semiconductor substrate, including: etching a polysilicon layer above the well region through a window for a body region; and forming spacers at side walls of the polysilicon layer, to define positions of source regions in the well region.

Abstract: A COT switching converter includes a switching circuit having a main switch, an on-time control circuit configured to generate an on-time control signal, a comparing circuit, a logic circuit and a reference voltage adjusting circuit. The comparing circuit compares a reference voltage with a feedback signal indicative of output voltage of the switching circuit to generate a comparison signal. Based on the on-time control signal and the comparison signal, the logic circuit generates a control signal of the main switch. The reference voltage adjusting circuit generates the reference voltage based on a basic reference voltage and the control signal, in each switching cycle of the switching converter, the reference voltage is pulled down when the main switch is turned ON and increases with a slew rate until the main switch is turned ON again in the next switching cycle or the reference voltage increases to a maximum value.

Abstract: A bootstrap circuit integrated to a voltage converter integrated circuit (IC) and a voltage converter IC for a switch mode voltage regulator. The bootstrap circuit is used to provide a bootstrap voltage signal for driving a high side switch of the voltage converter IC. The bootstrap circuit has a pre-charger and a bootstrap capacitor. The pre-charger provides a first bootstrap signal to pre-charge a control terminal of the high side switch, and the bootstrap capacitor provides a second bootstrap signal to enhance the charge of the control terminal of the high side switch.

Abstract: A switching power supply system includes a switching converter, to convert an input voltage into an output voltage and to generate a switching signal; a feedback circuit, to generate a feedback signal; an error amplifier to generate an error signal; a triangle signal generator to generate a triangle signal; a constant on time control circuit to receive error signal and the triangle signal, and to generate a constant on time control signal to control power switch; in the system. The triangle signal has a DC bias based on either a soft start signal or a second reference signal. The system could perform soft start function and meanwhile keep matching between the error signal and the triangle signal.

Abstract: A two-channel LED driver adopts one power stage to provide a constant drive current to drive a first channel LED and a second channel LED, and to provide a power supply voltages to power a smart module. The two-channel LED driver controls the total current flowing through the first channel LED and the second channel LED according to a first dimming signal input by users through the smart module, and controls the dimming ratio between the two channels according to a second dimming signal. The two-channel LED driver provides high performance with simple circuit structure.

Abstract: A multiphase power supply includes several constant ON-time (COT) DC-DC converter integrated circuits (ICs). One of the COT DC-DC converter ICs generates a synchronization signal, which is received in parallel by the other COT DC-DC converter ICs. Two or more COT DC-DC converter ICs are turned ON at the same time in synchronization with the synchronization signal (e.g., an edge of a pulse of the synchronization signal) that is received in parallel and with another synchronization signal that is propagated from one COT DC-DC converter IC to another.

Abstract: Control method and circuit for resonant converters with capacitive protection. When a resonant converter enters into a capacitive mode, a high-side switch and a low-side switch of the resonant converter are turned off. After the high-side switch and a low-side switch are turned off for N switching cycles, the high-side switch is turned on once a current sense signal flowing through a resonant inductor of the resonant converter is increased to a zero-crossing threshold during an ascent stage of the current sense signal, and the low-side switch is turned on once the current sense signal is decreased to the zero-crossing threshold during a descent stage of the current sense signal.

Abstract: A short-circuit protection method for a boost converter is disclosed. In this method, a switch of a switching circuit of the boost converter is turned on and a control voltage with a gradually increasing magnitude is supplied to control a short-circuit protection switch coupled between an input voltage and the switching circuit when the boost converter starts up. Then, a current flowing through the switch is detected and compared with a predetermined value. The switch is turned off and a preset time period is initiated if the current is higher than the predetermined value. It is detected whether a short-circuit event occurs at an output terminal of the boost converter at the end of the preset time period. If the short-circuit event occurs, the short-circuit protection switch is then turned off.

Abstract: A lateral DMOS device with peak electric field moved below a top surface of the device along a body-drain junction is introduced. The LDMOS has a deep body and a drift region formed by a series of P-type and N-type implants, respectively. The implant doses and depths are tuned so that the highest concentration gradient of the body-drift junction is formed below the surface, which suppresses the injection and trapping of hot holes in the device drain-gate oxide region vicinity, and the associated device performance changes, during operation in breakdown.