Cross complementing PWM driving waveform generating method and circuit

Abstract

The invention discloses a cross complementing PWM (Pulse Width Modulation) driving waveform generating method. The method comprises the following steps: S100, based on the rising edge and the falling edge of two frequency modulation PWM drive signals, the two frequency modulation PWM drive signals are subject to frequency halving to obtain two groups of four signals; S200, based on the generated two groups of signals, the first group of signals are subject to XOR operation to obtain a first sub-signal, and the second group of signals are subject to XOR operation to obtain a second sub-signal; S300, the rising edges and the falling edges of both the first sub-signal and the second sub-signal are utilized, and the logical operation of a trigger, an AND unit and an OR unit is performed to obtain a first sub-group of signals and a second sub-group of signals; and S400, the first sub-signal is subject to AND operation with the first sub-group of two signals respectively after being reversed, to obtain a first signal and a second signal, the second sub-signal is subject to AND operation with the second sub-group of two signals respectively after being reversed, to obtain a third signal and a fourth signal, and the four signals are four PWM driving square waves with both crossed 90-degree phase angles and dead zones.

Description

technical field [0001] The invention relates to the field of power supply control, in particular to a method for generating interleaved complementary PWM driving waveforms and a circuit thereof. Background technique [0002] The current global energy shortage, under the condition that energy demand per unit area continues to rise, the market puts forward new demands for high efficiency and high power density for switching power supply products. The resonant topology, especially the LLC resonant topology, has become the first choice in the industry to realize high-efficiency, high-power-density switching power supply solutions. It has the advantages of wide range, soft switching operation, and fewer main power components. as attached figure 1 The half-bridge resonant topology shown, with the figure 2 The full-bridge resonant topology is easy to implement in small and medium power supplies (below 2kW), but high-power supplies pose challenges to the design of magnetic compon...

AI Technical Summary

Problems solved by technology

[0005] At present, the interleaved parallel control function in the industry is usually implemented digitally based on programmable logic device chips such as FPGA or DSP. This method is often difficult to implement and the cost is high.

At present, the low-cost and simple-designed analog resonant control chips commonly used in the market basically only have two complementary frequency-modulated PWM signal outputs, such as figure 1 as well as figure 2 As shown, this makes it impossible to control the interleaved parallel topology

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