Abstract: A linear voltage regulator includes an error amplifier receiving an operational voltage and provided a control signal, a pass device controlled by the control signal and providing a load voltage from a power supply, and a leakage circuit controlled by the control signal and consuming a drive-back current. Since the linear voltage regulator includes the leakage circuit, a drive-back current created can be grounded via the switch transistor of the leakage circuit. Thereby an impedance calibration of termination transistors will be normal, and a life span of electronic components will be protected.

Abstract: A weak battery warning circuit includes a warning circuit for generating an alarm; a battery having a cathode connected to ground; and a controlling circuit comprising a transistor, the transistor having an emitter for receiving an input voltage, a base connected to an anode of the battery via a base resistor, and a collector connected to the warning circuit and also connected to ground via a collector resistor. When the voltage of the battery reduces to a predetermined value, the controlling circuit controls the warning circuit to alarm.

Abstract: A control circuit for command signals of a clock generator includes a power supply end, an output end, a control end, a diode, a first resistor and a second resistor. The first resistor, the diode, and the second resistor are connected in series between the power supply end and the ground. The diode has an anode connected to the first resistor and a cathode connected to the second resistor. The control end is connected to a node between the diode and the second resistor; the output end is connected to a node between the diode and the first resistor. The output end outputs the command signals to the clock generator.

Abstract: A power supply for a bus interface is provided. The power supply comprises: an input terminal; an output terminal; a fuse providing over-current protection; a diode providing over-voltage protection, a reverse breakdown voltage of the diode not less than a maximal voltage difference of the output terminal and the input terminal, the diode connected to the fuse in series between an input terminal and an output terminal; and a plurality of capacitors filtering noise, one end of each of the capacitors connected to a node between the fuse and an anode of the diode, and another end of each of the capacitors is grounded. The power supply can provide effective over-voltage protection because a reverse breakdown voltage of the diode is not less than a maximal voltage difference of the output terminal and the input terminal. In addition, the power supply has a low cost of manufacture.

Abstract: A voltage providing circuit includes a protective circuit and a power supply circuit. The protective circuit includes a first transistor. A first control signal is input to a collector of the first transistor, a second control signal is input to a base of the first transistor, an emitter of the first transistor is grounded. The collector of the first transistor is connected to the power supply circuit. The second control signal and the first control signal jointly control the power supply circuit to be turned on or turned off. When the second control signal is at a low level, the first transistor is turned off and the power supply circuit is turned off. When the second control signal is at a high level, the first transistor is turned on and the power supply circuit is turned on. Thus, the providing circuit can prevent the electronic component from being damaged when a computer is restarted.

Abstract: A power good signal generating circuit includes an NPN transistor, a first resistor, a second resistor, a third resistor, a first power source, and a second power source. The first resistor is connected between a base of the transistor and the first power source. The second resistor is connected between a collector of the transistor and the second power source. The third resistor is connected between an emitter of the transistor and ground. The collector is connected to an output for sending a PG signal and the emitter is connected to an input for receiving a control signal P.

Abstract: A supply voltage switching circuit for a computer includes a chipset, a first transistor and a second transistor. The chipset includes a first MOSFET and a second MOSFET. A 5V system voltage and a 5V standby voltage are respectively inputted to sources of the first MOSFET and the second MOSFET. Gates of the first MOSFET and the second MOSFET are respectively coupled to collectors of the first transistor and the second transistor. Emitters of the first transistor and the second transistor are coupled to a first terminal for receiving a control signal. A 1.8V standby voltage is separately inputted to bases of the first transistor and the second transistor. A 12V system voltage and the 5V standby voltage are respectively inputted to collectors of the first transistor and the second transistor. A second terminal is connected between the drain of the first MOSFET and the drain of the second MOSFET.

Abstract: A supply voltage switching circuit for a computer includes a chipset, a first transistor, a second transistor, and a third transistor. The chipset includes a first MOSFET and a second MOSFET. A 5V system voltage and a 5V standby voltage are respectively inputted to sources of the first MOSFET and the second MOSFET. Gates of the first MOSFET and the second MOSFET are respectively coupled to collectors of the second transistor and the third transistor. A base of the first transistor is coupled to a terminal for receiving a control signal from the computer. The 5V standby voltage is inputted to a collector of the first transistor. Bases of the second transistor and the third transistor are coupled to the collector of the first transistor. A 12V system voltage and the 5V standby voltage are respectively inputted to collectors of the second transistor and the third transistor.

Abstract: A method for building a model of a multi-phase PWM-based converter is disclosed. The method includes the steps of: defining circuit diagrams and electronic characteristics of a circuit of the multi-phase PWM-based converter; defining configuration of a model of the multi-phase PWM-based converter, and defining characteristics of the model according to the circuit diagrams and the electronic characteristics; and building the model of the multi-phase PWM-based converter.

Abstract: A linear voltage regulator provides a regulated load voltage to a load. In a preferred embodiment, the linear voltage regulator includes: a regulating circuit for receiving an input voltage and providing an output voltage to a load, the regulating circuit being driven by a driving voltage; and two resistors connected to each other in series receiving the output voltage and providing an adjusting current to the regulating circuit. The linear voltage regulator is capable of providing a greater current to the load, and having a wide range of input voltages.

Abstract: A linear voltage regulator is provided for providing an output voltage to a load. In a preferred embodiment, the linear voltage regulator includes: a pass element for receiving an input voltage and providing an output voltage to a load, the pass element being adapted to be controlling by a controlling voltage; two resistors connected to each other in series for receiving the output voltage and providing a voltage reference; and a feedback circuit for receiving the voltage reference and providing the controlling voltage to the pass element. The linear voltage regulator is capable of providing a steady output voltage to the load, and a cost thereof being down at the same time.