A single-input and double-output pulse width modulation signal generating circuit

Abstract

The invention discloses a single-input double-output pulse width modulation (PWM) signal producing circuit, comprising a phase inverter (101), a regulating circuit (102), a first PWM output circuit (105) and a second PWM output circuit (106), wherein the phase inverter (101) is connected with a PWM port of a microcontroller; the regulating circuit (102) is electrically connected with the phase inverter (101); the first PWM output circuit (105) is electrically connected with the regulating circuit (102) and a first reference circuit (103); the second PWM output circuit (106) is connected with the regulating circuit (102) and a second reference circuit (104); one end of the first reference circuit (103) is connected with an external power source; the other end of the first reference circuit (103) is grounded through the second reference circuit (104). The single-input double-output pulse width modulation signal producing circuit has the beneficial effect that the microcontroller only uses one PWM port to control two switch elements of a same bridge arm and produce dead-time, so that the PWM port of the microcontroller can be effectively saved.

Description

technical field [0001] The invention relates to the technical field of drive control of switching devices, and more specifically, to a single-input and double-output pulse width modulation signal generating circuit. Background technique [0002] In the fields of household appliances, industrial control, power supply, etc., it is often necessary to control multiple switching devices at the same time, so multiple PWM (PulseWidthModulation, pulse width modulation) ports are required. When a single microcontroller is used for control, the PWM ports are not enough. Usually The method of increasing the number of microcontrollers is to increase the number of PWM ports. This method not only needs to solve the communication problem between multiple microcontrollers, but also increases the complexity of the system control and also increases the cost. [0003] In the prior art, the microcontroller usually outputs two complementary control signals to control the two switching elements o...

AI Technical Summary

Problems solved by technology

Taking the three-phase AC motor as an example, the current domestic motor control scheme mainly uses the DSP produced by TI manufacturer as the main control chip, configures the 6-way PWM peripheral of the chip through software to generate modulation waves, and then controls the switching elements to complete the electronic commutation At the same time, the dead time is also completed through the configuration register. Although the method of configuring the PWM peripheral of the DSP through software is relatively simple in control, it needs to occupy 6 PWM port outputs. For some applications that require a large PWM port, Such a design obviously cannot meet the needs of use. For example, in the case where multiple analog outputs are required while controlling the motor, the best way for analog output is to reflect the output through the pulse width change of the PWM port, and the DSP with more PWM ports Its cost will also increase significantly

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