Southeast University

Youshan Jin

Longxing Shi

Weifeng Sun

Shengli Lu

Shen Xu

Miao Yang

Sichao Liu

A switching power supply with a quick transient response is provided. A hysteretic control loop which comprises a hysteretic controller () and a control signal gate () is added to the original PWM control loop of the switching power supply. The hysteretic controller () is used to detect an output voltage (Vout) of the switching power supply and compare the output voltage (Vout) of the switching power supply with a reference voltage (Vref). When a load current (Iout) of the switching power supply is suddenly changed, the output voltage (Vout) of the switching power supply fluctuates. If the output voltage (Vout) of the switching power supply is in a setting range of the hysteretic voltage, output terminals (SELp, SELn) of the hysteretic controller () are in a low potential, and the control signal gate () selects output signals (Qp, Qn) from a PWM controller () as input signals of a gate signal drive circuit (). If the fluctuation of the output voltage (Vout) of the switching power supply exceeds the setting range of the hysteretic voltage, an output terminal (SELp, SELn) of the hysteretic controller () outputs a high potential, and the control signal gate () selects output signals (Qp, Qn) of the hysteretic controller () as input signals of the gate signal drive circuit (), so the operation of switching tubes () at the power lever () of the switching power supply is controlled to stabilize the output voltage (Vout).

Switching power supply with quick transient response

A switch level circuit () with dead time self-adapting control, which minimizes the switching loss in a switching power supply converter with synchronous rectification by changing a dead time between a high-side control transistor () and a low-side synchronous rectifying transistor (). The switch level circuit () includes the high-side control transistor () and the low-side synchronous rectifying transistor () which are controlled to be on and off by external control signals, and a waveform with a given duty cycle is outputted at a node (LX) between the two transistors. The switch level circuit () also includes a control module for adjusting the dead time. The control module comprises a sampling circuit () for detecting the current dead time at the node (LX), an adjusting circuit () for buffering and converting the sampling voltage sampled by the sampling circuit (), and a controlled delay unit () equipped with an external control input terminal, wherein the controlled delay unit () delays an external control signal and outputs the delayed signal to a controlled terminal of the low-side synchronous rectifying transistor () as a control signal. The switch level circuit () has simple structure, better performance and wide application range.

Switch level circuit with dead time self-adapting control

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Nanjing, China

Youshan Jin