Infineon Technologies Austria Ag

Infineon Technologies Ag

Kok Kee Lim

Yong Siang Teo

Xiaowu Gong

Yi He

Xiao Wu Gong

Jing Hu

Meng Kiat Jeoh

Junyang Luo

Winson Siew Teng Wong

Siew Teng Winson Wong

Tuck Meng Chan

Circuits and methods within a switched-mode power supply (SMPS) controller are provided. The SMPS controller includes an SMPS power stage which is integrated within the same package, and which has a first power switch. The first power switch is used to supply current to a power supply for the SMPS controller during a start-up phase of the SMPS, thereby charging this power supply prior to normal operational mode of the SMPS. A lead of the SMPS controller is connected to a control terminal of the first power switch during the start-up phase. After the start-up phase, this same lead is instead routed to an input source voltage monitor, and is used for detecting overvoltage or undervoltage conditions at the SMPS input power source.

Switched-mode power supply controller using a single pin for both input voltage sensing and control of power supply charging

Techniques are described for controlling an amount of current flowing through one or more light-emitting-diodes (LEDs), without sensing input and/or output voltage, so that the amount of current flowing through the one or more LEDs is approximately equal to a target current level. The techniques provide for coarse and fine tuning of the amount of time a transistor, through which the current flows, is turned on to control the amount of current flowing through the one or more LEDs.

Universal input and wide output function for light emitting diode (LED) driver

This disclosure relates to a switching power supply with regulated voltage suppression to reduce transformer audio noise. The switching power supply is operable to be fed a zero crossing voltage and to generate an output voltage. The output voltage may have a voltage level set using a modulated gate signal. A circuit is provided to reduce audio noise in a switching power supply by setting a ringing suppression time of the modulated gate signal to a first time period when the zero crossing voltage is below a predetermined voltage threshold and to a second time when the zero crossing voltage is above the predetermined threshold voltage.

System and method for suppressing a settling voltage in a switched mode power supply

Methods, devices, and circuits are disclosed delivering a first level of output voltage to a rechargeable battery from a battery charger, the rechargeable battery is coupled to the battery charger by a charging cable. The methods, device, and circuits may further be disclosed applying, in response to an indication of an altered output voltage, a compensation current to one or more elements of the battery charger including a zero crossing (ZC) pin and a selected resistor, the selected resistor is defined by the charging cable coupling the battery charger to the rechargeable battery, and applying the compensation current to the ZC pin and the selected resistor causes an adjustment of the output voltage from the first level of output voltage to a second level of output voltage corresponding to the voltage drop from the impedance of the selected charging cable.

Cable compensation by zero-crossing compensation current and resistor

In accordance with an embodiment, a method of operating a switched-mode power supply includes synchronously rectifying a current in a secondary side of the switched-mode power supply by detecting a voltage drop of a secondary winding of a transformer and activating a semiconductor switch coupled to the secondary winding when the voltage drop is detected. The method also includes determining a digital signal transmitting the digital signal to a controller coupled to a primary winding of the transformer by switching the semiconductor switch in accordance with the digital signal.

System and method for a switched-mode power supply

Devices, systems, and methods for improving a current spread of a light emitting diode (LED). Some aspects including a peak detector and a variable gain amplifier coupled to the peak detector and configured to amplify an output of the peak detector. The variable gain amplifier controlled by a gain selector, coupled to the variable gain amplifier by varying the gain of the variable gain amplifier based on an on time of a signal.

Propagation delay compensation for floating buck light emitting diode (LED) driver

This disclosure relates to a switching power supply with regulated voltage suppression to reduce transformer audio noise. A switched mode power supply (SMPS) may supply power at different levels according to output loads. A switching frequency of the SMPS may be adjusted according to the output load. The switching may be subject to a ringing suppression time, a maximum on time, and a maximum switching period. By controlling the switching frequency subject to these quantities, the audible noise of an SMPS may be reduced or eliminated.

Techniques to reduce audible noise in a power supply transformer

A system and method for operating power supplies. A method comprises altering a current sense (CS) signal, turning off a switch of the converter in response to a determining that the CS signal is greater than or equal to a first threshold, and leaving on the switch of the converter in response to a determining that the CS signal is less than the first threshold.

System and method for power conversion

An integrated circuit includes an operational amplifier configured to receive a current sense voltage (V) at a first input and an offset voltage at a second input. A comparator is coupled to the operational amplifier and adapted to receive at a first input an output voltage signal (V) of the operational amplifier. A voltage limiting circuit is configured to receive a regulation voltage. A fold back correction circuit is coupled to the voltage limiting circuit and to a second input of the comparator. A pulse width modulator circuit is coupled to the comparator and is adapted to receive the output of comparator.

Method and apparatus for regulating power in a flyback converter

An oscillator structure has a sync signal processor with an input interface for an external clock based sync signal and an output interface for a duty cycle indication signal depending on a signal property of the sync signal and an oscillator with an input interface for the duty cycle indication signal and the sync signal and an output interface for an oscillation signal synchronized with the external clock and having a duty cycle adjusted according to the duty cycle indication signal.

Oscillator structure

In a preferred embodiment, there is provided a switched mode power supply operable in start-up mode, normal mode and standby mode. The power supply may comprise a transformer having a primary winding on a primary side and a secondary winding on a secondary side, the primary winding being coupleable to a DC input voltage, and circuitry on the secondary side being arranged to provide a DC output voltage; and a power controller. The power controller may comprise a regulation controller for regulating a DC supply voltage on a supply line during standby mode, and a high voltage device coupled to the DC input voltage and the supply line. The current through the high voltage device to the supply line, during standby mode, may be controlled by the regulation controller. During standby mode, when the supply voltage is greater than or equal to a reference voltage, the current through the high voltage device to the supply line is substantially zero. When the supply voltage is less than the reference voltage, the greater the difference between the supply voltage and the reference voltage, the greater the current through the high voltage device to the supply line. In other preferred embodiments, there is also provided the power controller itself and a method for regulating a supply voltage during standby mode.

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Singapore, Singapore

Kok Kee Lim