Shanghai Bright Power Semiconductor Co., Ltd.

Analog Devices International Unlimited Company

Analog Devices Global Unlimited Company

United Automotive Electronic Systems Co. Ltd.

Yihui Chen

Zhen Zhu

Xiaoru Gao

Haifeng Miao

Yanmei Guo

Yuehui Li

Rulong Jiang

Jie He

Hanfei Yang

Shungen Sun

Brandon Day

Danzhu Lu

Liqiang Hu

Hong Zhang

Pengfei Lu

Alex Xiao

Wendy Mao

A control circuit, a control chip and a power supply device are disclosed by the present invention. The control circuits are used for control of a constant-voltage closed-loop which causes a voltage of a voltage feedback signal obtained from an output voltage to approach a voltage of a reference voltage signal obtained from a base voltage and thereby achieves a constant-voltage output. In addition, when a sampled current obtained from an output current is higher than a predetermined current, or when output power is higher than a predetermined power, the control circuit increases the voltage feedback signal or decreases the reference voltage signal, causing the constant-voltage closed loop to decrease the output voltage and the output current and thereby achieving a limited output current and limited output power.

Control circuit, control chip and power supply device

A control circuit, system and method for switched-mode power supply are disclosed, the control circuit is for driving a first switch to convert an input voltage into an output voltage. The control circuit includes an on-time control unit, which receives a first signal characterizing switching frequency of first switch and a second signal characterizing current flowing through first switch and responsively generates a signal indicative of a turn-off instant for first switch. When a peak value of the current flowing through the first switch drops below a predefined value, the on-time control unit determines the turn-off instant for the first switch based on the first signal so that the switching frequency of the first switch is maintained at a target frequency. This design can effectively avoid the generation of audible noise, stabilize the output voltage against load changes while maintaining desirable efficiency, and ensure operational safety of the switched-mode power supply.

Control circuit, system and method for switched-mode power supply

A control circuit for an isolated power supply is disclosed, the control circuit includes a secondary-side drive signal generator, a secondary-side transistor switch turn-off detector and a primary-side control signal generator. The primary-side control signal generator is configured to: determine a second turn-on instant referring to an turn-off instant of the secondary-side synchronous rectification transistor from the turn-off acknowledgement signal; determine a first turn-on instant referring to a supposed turn-on instant for the primary-side transistor switch from the feedback signal of the output voltage of the isolated power supply; and determine the turn-on instant for the primary-side transistor switch from the second turn-on instant or the first turn-on instant whichever is later, and responsively generate the primary-side transistor switch control signal. This control circuit can effectively avoid shoot-through of primary- and secondary-side transistor switches at the cost of only insignificantly compromised feedback adjustment accuracy.

Control circuit for an isolated power supply

An output short-circuit protection method, a power management chip and a switched-mode power supply are disclosed. When current accumulation has occurred in a power transistor, the number of consecutive current pulses during which the current accumulation occurred is counted. Upon the number of consecutive current pulses reaches a preset value, a regulation interval spanning switching periods is triggered, for at least some of the switching periods, the leading-edge blanking time is shortened or cancelled. In this way, an excessively large current flowing through the power transistor is prevented. Compared with existing fault response measures for power management chips, restart of the power supply and adjustment of the system timing are not needed, allowing easier implementation. Further, the automatic restart during chip start up due to false triggering as found in the existing measures for power management chips is circumvented.

Output short-circuit protection method, power management chip and switched-mode power supply

Isolated power supply control circuits, isolated power supply and control method thereof are disclosed, the control circuit for controlling an isolated power supply includes a secondary-side control signal generator and a primary-side control signal generator. The secondary-side control signal generator produces a secondary-side transistor switch control signal containing information about a turn-off instant of a secondary-side synchronous rectification transistor, which serves as a second turn-on instant. The primary-side control signal generator derives, from a feedback signal, a supposed turn-on instant for a primary-side transistor switch, which serves as a first turn-on instant. The primary side turn-on signal generator further derives a turn-on instant for the primary-side transistor switch from the second or first turn-on instant whichever is later and responsively generates a primary-side transistor switch control signal. This control circuit can effectively avoid shoot-through of primary- and secondary-side transistor switches at the cost of only insignificantly compromised feedback adjustment accuracy.

Isolated power supply control circuits, isolated power supply and control method thereof

A switch-mode power supply (SMPS), an SMPS system and a power supply method for an SMPS system are disclosed. The SMPS controller includes an output-voltage power supply unit, a built-in energy storage unit and a logic control unit. The output-voltage power supply unit is configured to charge the built-in energy storage unit using an output voltage from the SMPS system so that the built-in energy storage unit can provide an operating voltage for the logic control unit. The use of a stand-off energy storage capacitor can be dispensed with, and the use of the output voltage as a power supply is enabled. As a result, significant reductions in overall and standby power dissipation are achieved. In addition, the SMPS controller may further include a high-voltage power supply unit, which provides a hybrid power supply solution, together with the output-voltage power supply unit.

Switch-mode power supply (SMPS) controller, SMPS system and power supply method for SMPS system

A control circuit, system and method for switched-mode power supply are disclosed, the control circuit is for driving a first switch to convert an input voltage into an output voltage. The control circuit includes an on-time control unit, which receives a first signal characterizing switching frequency of first switch and a second signal characterizing current flowing through first switch and responsively generates a signal indicative of a turn-off instant for first switch. When a peak value of the current flowing through the first switch drops below a predefined value, the on-time control unit determines the turn-off instant for the first switch based on the first signal so that the switching frequency of the first switch is maintained at a target frequency. This design can effectively avoid the generation of audible noise, stabilize the output voltage against loading changes while maintaining desirable efficiency, and ensure operational safety of the switched-mode power supply.

Techniques for compensating temperature-dependent aspects of oscillator circuits are provided. In an example, an oscillator circuit can include an oscillator capacitor, a comparator and overshoot compensation circuitry for providing an oscillation period insensitive to a temperature-dependent comparator overshoot. The oscillator capacitor can be charged during a charging portion of the oscillation period and can be discharged during a discharging portion of the oscillation period. The comparator can determine when the oscillator capacitor has been charged to a first threshold. The overshoot compensation circuitry can store an indication of temperature-dependent comparator overshoot and, in response, generate and apply an adjustable reference voltage or pre-charge to a terminal of the oscillator capacitor.

Oscillator temperature compensation techniques

The subject disclosure includes paralleling of monolithic embedded low drop-out (LDO) linear regulator power rails to provide additional load current, while maintaining accurate current sharing and balancing between the paralleled LDOs without additional power consumption for different load current requirements. Lossless current sensing is used to sense the current for each channel. An offset generator compares the voltages for a master channel and one or more slave channels, and generates an offset voltage according to the sensed error. The offset voltage is added between an input reference voltage and an output regulated voltage to cancel the offset of each channel, so the current of each channel is substantially the same. The lossless current sensing can be realized with equivalent series resistance compensation or current limit sensing. The offset generator can be realized with a resistor and current mirror topology or an input pair added to an error amplifier input.

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Shanghai, China

Yihui Chen