Infineon Technologies Austria Ag

Infineon Technologies Ag

Yong Siang Teo

Xiaowu Gong

Kok Kee Lim

Xiao Wu Gong

Yi He

Andrey B Malinin

Renato Bessegato

Siu Kam Kok

Tuck Meng Chan

Siew Teng Winson Wong

Winson Siew Teng Wong

Gerald Deboy

Michael Herfurth

Cheow Guan Lim

Zan Wang

Meng Kiat Jeoh

Ming Ping Mao

Siu Kam Eric Kok

A power supply includes a primary winding, a secondary winding, a switch, and a controller. The secondary winding is magnetically coupled to the primary winding. The switch is coupled to the secondary winding and controls a state of current through the secondary winding. The controller controls the state of the switch based on an integrator voltage derived from monitoring a voltage from the secondary winding. For example, the controller activates the switch to an ON state in response to detecting a condition in which the magnitude of the monitored voltage of the secondary winding crosses a threshold value such as a magnitude of an output voltage produced from the secondary winding.

Power supply and winding switch control via an integrator voltage

Techniques to send digital information from the secondary side to the primary side of a power converter, such as a flyback power converter, without the need for a separate, isolated communication channel. The power converter of this disclosure may send digital information from secondary side to the primary side through a power transformer while the power converter operates in a mixed mode scenario, e.g. critical conduction mode (CRCM) and discontinuous conduction mode (DCM). In CRCM, a controller circuit for the power converter may encode digital information by modulating the diode conduction time in a switching cycle. In DCM, the controller circuit may encode digital information by modulating the period of time for each switching cycle, e.g. increased period, decreased period or no change to the period.

Method of communication through a flyback power transformer using a zero voltage switching pulse in CRCM mode

A synchronous rectifier includes: an integrator configured to integrate a voltage across a secondary side winding of a transformer over an integral period having an expected zero integral value; a first comparator configured to detect an end of a demagnetization phase of the secondary side winding based on diode detection; and a digital circuit configured to adjust a channel gain of the synchronous rectifier based on an integration error at the end of the integral period, the integration error corresponding to the difference between the integrated voltage at the end of the integral period and the expected zero integral. Corresponding methods of gain tuning and a power converter are also described.

Gain tuning for synchronous rectifiers

Voltage converter controllers, voltage converters and methods are discussed regarding the adjustment of an on-time of an auxiliary switch of a voltage converter. First and second voltages are measured before a primary switch of the voltage converter is turned on and while the primary switch is turned on, and the on-time is adjusted based on the voltages.

Voltage converter controller, voltage converter and method for operating a voltage converter

An example method includes storing a peak voltage level, a valley voltage level, and a frequency of a signal that corresponds to an alternating current (AC) signal across a capacitor; periodically determining whether a current peak voltage level of the signal is different than the stored peak voltage level of the signal or a current valley voltage level of the signal is different than the stored valley voltage level of the signal; determining, based on whether the current peak voltage level of the signal is different than the stored peak voltage level or the current valley voltage level of the signal is different than the stored valley voltage level, whether the AC signal has been removed from the capacitor; and in response to determining that the AC signal has been removed from the capacitor, discharging the capacitor.

Capacitor discharging

An integrated circuit may detect a pin voltage at a selector pin. The integrated circuit may compare the pin voltage to a threshold voltage. The integrated circuit may selectively perform primary side voltage regulation or secondary side voltage regulation, to regulate a voltage supplied to an electrical load coupled to the integrated circuit, based on comparing the pin voltage and the threshold voltage.

Integrated circuit with selection between primary side voltage regulation and secondary side voltage regulation

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

In accordance with an embodiment, a method of operating a switched-mode power supply includes turning on a semiconductor switch coupled to a primary winding of a transformer for a first time period of a first cycle, turning off the semiconductor switch for a second time period of the first cycle, detecting a change in slew rate of a voltage at an output node of the semiconductor switch, determining a switch turn-on time based on detecting the change in the slew rate, and turning on the semiconductor switch at the determined switch turn-on time for a first time period of a second cycle.

System and method for a switched-mode power supply

In some examples, a circuit is configured to receive an input signal and deliver, based on the input signal, a charging current to a capacitor. The circuit may be further configured to receive an output voltage that indicates a charge on the capacitor. The circuit may be further configured to determine that the output voltage is shorted to a reference ground. The circuit may be further configured to reduce, based on determining that the output voltage is shorted to the reference ground, the charging current.

Protection and management of a power supply output shorted to ground

Techniques are described to adjust an amount of time a switch is turned off to control power delivered to a load. In some examples, the amount of time the switch is off includes a delay count value and a set count value based on an output power level. In some examples, the amount of time the switch is off includes a zero crossing delay value based on the input voltage level. Both of these example techniques increase the switching efficiency of the system.

Multi-mode quasi resonant converter

In accordance with an embodiment, a switched-mode power converter includes a switch, a freewheeling diode coupled between an output terminal of the switch and a power supply input node, an inductor coupled between the output terminal of the switch and a power supply output node, and a passive network having a first terminal coupled to the output terminal of the switch, a second terminal coupled to a power supply output node, and a third terminal coupled to a reference terminal of the switch. A method includes measuring a first voltage at a fourth terminal of the passive network when the switch is on; measuring a second voltage at the fourth terminal of the passive network when the switch is off; and estimating an output voltage between the power supply output node and the reference terminal of the switch based on the first voltage and the second voltage.

Representative implementations of devices and techniques provide a reduction in the spread of a bandgap voltage of a bandgap reference circuit. The biasing current for a target bipolar device is conditioned by passing it through one or more like bipolar devices prior to biasing the target bipolar device.

Bandgap voltage circuit with low-beta bipolar device

Methods, devices, techniques, systems, and integrated circuits are disclosed for variably controlling a switch on time for a driver, which may enhance iTHD. In one example, a device includes an input voltage sensor configured to detect an input voltage, and a variable switch on time generator, operatively connected to the input voltage sensor to receive a signal indicative of the input voltage. The variable switch on time generator is configured to determine a variable switch on time based at least in part on the detected input voltage, and output the determined variable switch on time for controlling switch on timing of a driver switch.

Buck converter electronic driver with enhanced iTHD

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.

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Singapore, Singapore

Yong Siang Teo