Hybrid digital pulse width modulator with delay chain optimization

Abstract

A hybrid digital pulse width modulator with delay chain optimization function belongs to the technical field of power electronics. A coarse adjustment module uses a comparator to realize the conversion between the comparison state and the clock state. In the comparison state, the counting signal and the high-order signal of the counting clock signal are compared. In the clock state, the counting clock signal is corrected and used as the timing control of the calibration unit in the fine adjustment module. A fine adjustment module includes a calibration unit, a calibration output unit, a decoder, a delay chain and a multiplexer, wherein, the calibration unit generates a calibration code according to the delay signal fed back by the delay chain as a calibration signal, the calibration code is decoded by the decoder, the path of the delay chain is controlled, and finally, the multiplexer selects the corresponding output of the delay chain as an output signal of the fine-tuning module according to the low-order signal. The digital logic module generates a pulse width modulated signal according to the output signals of the coarse modulation module and the fine modulation module. The invention optimizes the delay time and can obtain the pulse width modulated signal with higher accuracy.

Description

technical field [0001] The invention belongs to the technical field of power electronics, and in particular relates to a hybrid digital pulse width modulator with a delay chain optimization function. Background technique [0002] A digital pulse width modulator (Digital Pulse With Modulation, DPWM) is responsible for converting a digital signal into a pulse signal with a certain duty cycle. Its application is, for example, in a digital switching power supply. The digital compensator provides the input digital signal, and the output pulse signal is input to the power tube to control the switching time of the power tube in the power stage. By adjusting the switching time, the main circuit is finally regulated. The output voltage. The precision, area, power consumption and other indicators of the digital pulse width modulator DPWM are an important part of the application system indicators. The accuracy of the digital pulse width modulator DPWM directly determines the control ...

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Problems solved by technology

However, there will be a certain delay td between the start time of the delay chain and the rising edge of the clock, so that the final delay chain delay time is one count clock period minus td, which is less than the set value

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