Abstract: A control circuit for a power converting circuit includes a multifunctional pin, a pulse-width-modulation (PWM) signal generating circuit, a voltage detecting circuit and a zero current detecting circuit. The voltage detecting circuit detects a signal on the multifunctional pin. When the signal on the multifunctional pin is greater than a predetermined value, the voltage detecting circuit configures the PWM signal generating circuit to intermittently conduct a current switch of the power converting circuit. The zero current detecting circuit detects the signal of the multifunctional pin to determine the conduction status of the current switch. When the signal of the multifunctional pin is less than the predetermined value, the voltage detecting circuit configures the PWM signal generating circuit to turn off the current switch.

Abstract: A switching power converting apparatus includes a coil unit, a bipolar junction transistor (BJT) controlling power transfer through the coil unit, and a current sensing resistor sensing a current flowing through the BJT so as to produce a sensed voltage thereacross. A switching controller includes a current source supplying a first current, a current generating module generating, based on an input voltage associated with the sensed voltage, a second current, which is proportional to the current flowing through the BJT, a multiplexing module selecting one of the first and second currents as an output current, and a driving module outputting, based on the output current, a driving current, which is proportional to the output current, to the BJT to thereby conduct the BJT.

Abstract: An oscillator generates a clock signal according to a voltage, a current and a capacitance, and a frequency jitter circuit and method use a random number to modulate the voltage, the current or the capacitance, or a count value to modulate the capacitance, to jitter the frequency of the clock signal.

Abstract: A control circuit for a power converter has a current source, a sampling circuit, a signal processing circuit, a driving circuit, and a shared pin. The shared pin is used for coupling with a resistor and a switch. The current source, coupled with the shared pin, provides a current through the shared pin to the resistor in a first period. The sampling circuit, coupled with the shared pin, samples signals on the shared pin for generating a first sampling value and a second sampling value. The signal processing circuit, coupled with the sampling circuit, compares the first sampling value and the second sampling value. The driving circuit generates driving signals for conducting the switch. When the difference of the first sampling value and the second sampling value is less than a predetermined value, the signal processing circuit configures the driving circuit to intermittently conduct the switch in a second period.

Abstract: A switching power converting apparatus includes a voltage conversion module, a detecting unit, and a switching signal generating unit. The voltage conversion module converts an input voltage into an output voltage associated with a secondary side current, which flows through a secondary winding of a transformer and is generated based on a switching signal. The detecting unit generates a detecting signal based on the output voltage and a predetermined reference voltage. The switching signal generating unit generates the switching signal based on the detecting signal and an adjusting signal so that the secondary side current is gradually increased during a start period of the switching power converting apparatus.

Abstract: The present invention discloses a power factor correction circuit, a control circuit therefor and a method for driving a power factor correction circuit. The power factor correction circuit receives rectified power obtained by rectifying AC power, and corrects the power factor thereof. The power factor correction circuit includes an inductor, and it generates a reference signal as a limit for the inductor current. The reference signal is proportional to Comp/Vin, wherein Comp is a signal relating to a feedback signal, and Vin is a voltage signal relating to the AC power or the rectified power.

Abstract: An apparatus and a method for implementing a multiple function pin in a boundary conduction mode power supply, uses a same pin to switch a power switch and to achieve zero current detection to reduce pin count and save cost of a control integrated circuit. A first voltage is applied to the multiple function pin to turn on the power switch, and then a second voltage is applied to the multiple function pin after the power switch has been turned on for a first time, to thereby turn off the power switch. After the power switch has been turned off for a second time, a third voltage is applied to the multiple function pin keep the power switch off. Preferably, a tristate output driver is used to provide the first and second voltages, and a clamping circuit is used to provide the third voltage.

Abstract: A switching power converting apparatus includes a coil unit, a bipolar junction transistor (BJT) controlling power transfer through the coil unit, and a current sensing resistor sensing a current flowing through the BJT so as to produce a sensed voltage thereacross. A switching controller includes a current source supplying a first current, a current generating module generating, based on an input voltage associated with the sensed voltage, a second current, which is proportional to the current flowing through the BJT, a multiplexing module selecting one of the first and second currents as an output current, and a driving module outputting, based on the output current, a driving current, which is proportional to the output current, to the BJT to thereby conduct the BJT.

Abstract: A control circuit of a flyback power converter includes a first reference signal generating circuit for generating a first reference signal; a reference signal adjusting circuit for generating an adjustment signal according to the first reference signal and a test signal corresponding to an output voltage signal of the flyback power converter, and to generate a second reference signal according to the adjustment signal and the first reference signal; an error detection circuit for generating an error signal according to the second reference signal and a feedback signal; and a control signal generating circuit for generating a control signal according to the error signal to control operations of a power switch to thereby adjust the test signal. The feedback signal corresponds to a current flowing through a primary side coil of the power converter or a sensing voltage of an inductive coil of the power converter.

Abstract: A floating gate driver uses a single-end level shifter to translate a set signal and a reset signal induced by a rising edge and a falling edge of a switch signal to a common output terminal to generate an output voltage for a bistable circuit to generate a level shifted switch signal. Under control of a well transient detect signal asserted by detecting noise in the output voltage, a masking circuit between the single-end level shifter and the bistable circuit masks noise in the output voltage. This configuration has lower area penalty and better noise immunity.

Abstract: A floating gate driver uses a single-end level shifter to translate a set signal and a reset signal induced by a rising edge and a falling edge of a switch signal to a common output terminal to generate an output voltage for a bistable circuit to generate a level shifted switch signal. Under control of a well transient detect signal asserted by detecting noise in the output voltage, a masking circuit between the single-end level shifter and the bistable circuit masks noise in the output voltage. This configuration has lower area penalty and better noise immunity.

Abstract: A voltage converter circuit, includes: a power switch for generating a pulse-width-modulation (PWM) signal to drive a current load, wherein the PWM signal toggles between a first level and a second level; a sensing pin, receiving a first sensing signal when the PWM signal is at the first level, and receiving a second sensing signal when the PWM signal is at the second level; a parameter sampling and setting unit, having an input terminal coupling to the sensing pin, generating a default current or a default voltage on the sensing pin and sampling the second sensing signal to generate a sampling signal when the PWM signal is at the second level, and holding the sampling signal to set a parameter of the voltage converter circuit when the PWM signal is at the first level.

Abstract: A high voltage half-bridge driver circuit has a high voltage terminal and a floating node to be connected with a high side switch therebetween. When turning on the high side switch, a high voltage offset detection circuit detects a voltage related to the voltage at the floating node for triggering a zero voltage switching signal.

Abstract: A floating gate driver uses a single-end level shifter to translate a set signal and a reset signal induced by a rising edge and a falling edge of a switch signal to a common output terminal to generate an output voltage for a bistable circuit to generate a level shifted switch signal. Under control of a well transient detect signal asserted by detecting noise in the output voltage, a masking circuit between the single-end level shifter and the bistable circuit masks noise in the output voltage. This configuration has lower area penalty and better noise immunity.

Abstract: A switching power converting apparatus is capable of converting an input voltage to an output voltage, and includes a transformer, a primary side control module, and a secondary side control module. The secondary side control module utilizes voltage clamping techniques or current-drawing techniques to stop self-excited conversion from the input voltage to the output voltage when the output voltage is greater than a predetermined target voltage, or utilizes a non-self-excited conversion architecture.

Abstract: A bootstrap circuit includes: a charging voltage source; a charging diode, having an anode coupled to the charging voltage source; a high-voltage transistor, having a control terminal defined as a first connecting node and a channel coupled between a cathode of the charging diode and a bootstrap capacitor; a logic control circuit, having a first and a second logic outputs, and a logic input for receiving a charging command; a high-voltage control transistor, having a control terminal defined as a second connecting node and a channel coupled between charging voltage source and the first connecting node; a cut-off resistor, coupled between the first and the second connecting nodes; a charging control transistor, having a channel coupled between the second connecting node and a ground terminal, and a control terminal coupled to the second logic output; a control capacitor, coupled between the first connecting node and the first logic output.

Abstract: A mixed mode compensation circuit for a power converter generate a digital signal according to a reference signal and a feedback signal which is related to the output voltage of the power converter, convert the digital signal into a first analog signal, offset the first analog signal with a variable offset value to generate a second analog signal, and filter out high-frequency components of the second analog signal to generate a third analog signal for stable output voltage of the power converter. The mixed mode compensation does not require large capacitors, and thus the circuit can be integrated into an integrated circuit.

Abstract: A reverse shunt regulator includes a MOSFET connected between a cathode and an anode, a switch and a current source serially connected between the cathode and the anode, and an error amplifier having a positive input node to receive an internal reference voltage, a negative input node connected to the reference electrode, and an output node connected to a control electrode of the MOSFET. When the voltage of the reference electrode is within a range, the larger the voltage of the reference electrode is, the less the current of the MOSFET is. Application of this reverse shunt regulator to a flyback converter for output feedback will reduce the power loss in a green mode of the flyback converter.

Abstract: A power off delay circuit includes a switch connected between an external power input terminal and an internal power supply terminal, a capacitor connected to the internal power supply terminal, and a hysteresis comparator to switch the switch according to the voltages of the external power input terminal and the internal power supply terminal. During on-time of the switch, the external power input terminal is connected to the internal power supply terminal and the capacitor can be charged by the external power source. When the switch is off, the capacitor provides electric power for an internal circuit. Application of the power off delay circuit to an audio system may eliminate the turn-off pops of the audio system.

Abstract: A floating gate driver circuit includes a level shifter, a pass element, a bistable circuit and a control logic circuit, to shift the voltage level of a control signal from a lower one to a higher one. The level shifter or the pass element has loads dynamically controlled by the control logic circuit to filter malfunction caused by dv/dt noise induced by a floating node.