Chengdu Monolithic Power Systems Co., Ltd.

F.i.s. Fabbrica Italiana Sintetici S.p.a.

Lin Feng

Yuedong Chen

Naixing Kuang

Jiali Cai

Hui Li

Siran Wang

Pierluigi Padovan

Andrea Castellin

Lei Miao

Haishi Wang

Jiayou Ye

Liu Jiageng

Yibo Zhou

A controller of an isolated switching converter having a primary and secondary switch, the controller includes a valley detection circuit for providing a valley pulse signal in response to valleys of a resonant voltage, a pulse frequency modulation circuit for providing a pulse frequency modulation signal based on a feedback signal indicative of an output voltage, a primary on enable circuit for providing a primary on enable signal based on the pulse frequency modulation signal and valley pulse signal, a secondary logic circuit for generating a secondary control signal to control the secondary switch based on a primary off detection signal, a zero cross detection signal and the primary on enable signal, and a primary logic circuit for generating a primary control signal to control the primary switch based on a synchronous signal electrically isolated from the primary on enable signal.

Isolated switching converter with secondary side modulation and control method thereof

A driving circuit for driving a synchronous rectifier device. The driving circuit may include a controllable clamping circuit having a first terminal coupled to a sensing terminal of the driving circuit, a second terminal coupled to a reference ground terminal of the driving circuit, a third terminal coupled to a driving terminal of the driving circuit, and a control terminal configured to receive a supply indication signal indicative of a voltage potential at a supply terminal of the driving circuit. The third terminal of the controllable clamping circuit may be connected to the second terminal of the controllable clamping circuit when the supply indication signal indicates that the voltage potential at the supply terminal has not been established to maintain the synchronous rectifier device off.

Circuit for driving synchronous rectifier device with false turn on prevention

A control circuit having power limit for controlling an AC-DC voltage converter. The control circuit includes a first sensing circuit having an auxiliary winding used to sense a voltage on an inductive element of the converter to generate a first sensing signal, a second sensing circuit used to sense the current flowing through the inductive element to provide a second sensing signal, and a power limit circuit. The power limit circuit generates a power indication signal indicative of the input power of the converter based on the first sensing signal and the second sensing signal. When the power indication signal is larger than a power threshold, a controllable switch of the converter is turned off.

Control circuit having power limit for an AC-DC converter and integrated circuits thereof

A driving circuit and driving method for driving a synchronous rectifier. When a drain-source detecting voltage between a drain terminal and a source terminal of the synchronous rectifier reaches a second reference voltage, the driving voltage applied at a gate terminal of the synchronous rectifier is decreased to regulate the drain-source detecting voltage to a first reference voltage. The first reference voltage is lower than the second reference voltage. And when the drain-source detecting voltage reaches an off reference voltage, the synchronous rectifier is turned off.

Driving circuit allowing efficient turning-off of synchronous rectifiers

A synchronous switching converter with an energy storage component and a synchronous rectifier coupled to the energy storage component, having: a secondary control circuit configured to receive a slew rate threshold adjusting signal and a voltage across the synchronous rectifier, and to provide a secondary control signal; wherein the secondary control circuit detects a slew rate of the voltage across the synchronous rectifier, and maintains the synchronous rectifier being off when the slew rate of the voltage across the synchronous rectifier is lower than a slew rate threshold.

Control circuit for synchronous rectifier and the method thereof

A supply voltage generating circuit for generating a supply voltage signal to supply the active elements of an AC-DC voltage converter. The supply voltage generating circuit has a charging switch, a charging diode and a charging capacitor. When a main switch of the AC-DC voltage converter is turned on, the charging switch is turned on. Primary current flows through the charging switch and the main switch to the logic ground. When the main switch is turned off and the voltage across the charging capacitor is smaller than a charging threshold, the charging switch is kept on for a period of time and the primary current flows through the charging switch and the charging diode to the charging capacitor. When the period of time is expired or the supply voltage signal is larger than the charging threshold signal, the charging switch is turned off.

Supply voltage generating circuit and associated integrated circuit

A timing circuit used in lighting systems includes a first logic circuit, a first counter, a latching circuit and a judging circuit. The first logic circuit generates a first logic signal and a second logic signal based on a falling edge of a detecting signal. The first counter generates a first counting signal and a second counting signal based on the second logic signal, wherein the counting period of the first counting signal is longer than that of the second counting signal. The latching circuit samples and holds the first counting signal based on the first logic signal and provides a third counting signal. The judging circuit detects whether the second counting signal is equal to the third counting signal and provides a timing signal.

Timing circuits and driving circuits used in lighting systems

An LED driving apparatus includes a rectifier bridge generating a DC bus voltage, a bus capacitor coupled between the output terminal of the rectifier bridge and a reference ground, a voltage sensing circuit generating a voltage sensing signal indicative of the DC bus voltage, a bleeding circuit providing a bleeding current for the bus capacitor, a switching converter configured to convert the DC bus voltage into a driving signal to drive an LED, a dimming mode detector detecting whether the LED driving apparatus is coupled to a leading edge dimmer or a trailing edge dimmer based on the voltage sensing signal, and a bleeding control circuit generating a control signal to control the bleeding circuit based on the voltage sensing signal, the leading edge dimming mode signal and the trailing edge dimming mode signal.

Dimmer compatible LED driving apparatus with adjustable bleeding current

An LED driving apparatus includes a rectifier bridge generating a DC bus voltage, a bus capacitor coupled between the output terminal of the rectifier bridge and a reference ground, a tank element, a first transistor, a second transistor, a free-wheeling switch, an output capacitor, a voltage sensing circuit generating a voltage sensing signal indicative of the DC bus voltage, a bleeding circuit providing a bleeding current for the bus capacitor, and a bleeding control circuit generating a control signal to control the bleeding circuit based on the voltage sensing signal.

Dimmer compatible LED driving apparatus with bleeding circuit

A dimming mode detection method is used in an LED driving apparatus including a rectifier bridge providing a DC bus voltage and a switching converter configured to convert the DC bus voltage into a driving signal to drive an LED. The method involves: powering on the LED driving apparatus; sensing the DC bus voltage and generating a voltage sensing signal; comparing a rising time during which the voltage sensing signal increases from a second threshold voltage to a first threshold voltage with a first time threshold to detect whether the LED driving apparatus is connected to a leading edge dimmer; and comparing a falling time during which the voltage sensing signal decreases from a third threshold voltage to a fourth threshold voltage with a second time threshold to detect whether the LED driving apparatus is connected to a trailing edge dimmer.

Dimming mode detection method used in LED driving apparatus

A LED driving circuit, a control circuit and associated current sensing circuit. The control circuit has a sensing circuit, an estimation circuit, an amplifying circuit, a comparing circuit, a zero-cross detection circuit and a logic circuit. The sensing circuit is configured to sense a switching current flowing through at least one switch of a switching circuit to provide a first sensing signal. The estimation circuit is configured to process the first sensing signal to provide a feedback signal, wherein the feedback signal is indicative of a average current signal flowing through a LED. An average current flowing through the LED is regulated by sensing a switching current flowing through at least one switch.

LED driving circuit, control circuit and associated current sensing circuit

The present invention relates to a process for the synthesis of Moxifloxacin of Formula (I) and salts thereof by means of a process providing the coupling reaction of 1-cyclopropril-6,7-difluoro-1,4-dihydro-8-methoxy-4-oxo -3-quinolinic acid or ester thereof with (4aS, 7aS) -octahydro-1H-pyrrole[3,4-b]pyridine using a magnesium salt.

Growing community of inventors

Chengdu, China

Lin Feng