High-precision digital pulse width modulator composed of counter and fast and slow delay chain

Abstract

The invention provides a high-precision digital pulse width modulator composed of a counter and a fast and slow delay chain. The high-precision digital pulse width modulator is composed of a coarse adjustment module, an intermediate adjustment module, a fine adjustment module and an output module. The coarse adjustment module comprises a counter, a comparator and a D trigger, the intermediate adjustment module comprises a delay-locked loop DLL, a slow delay chain and a multiplexer MUXA, the fine adjustment module comprises a fast delay chain and a multiplexer MUXB, and the output module comprises a pulse generator PG1, a pulse generator PG2 and an RS trigger. The coarse adjustment module, the intermediate adjustment module, the fine adjustment module and the output module are connected insequence, digital duty ratio signals are divided into high-level data, intermediate-level data and low-level data and then input into the coarse adjustment module, the intermediate adjustment module and the fine adjustment module respectively, and finally the output module outputs analog duty ratio signals. The DPWM provided by the invention has the advantages of high conversion precision and lowpower consumption, small area and low overhead.

Description

technical field [0001] The invention belongs to the field of power electronics, and in particular relates to a high-precision digital pulse width modulator. Background technique [0002] In the digital control switching power supply, the digital pulse width modulator DPWM (Digital Pulse WithModulation) is a very important part. DPWM resolution (conversion accuracy), circuit area and power consumption are closely related to the performance of digital control switching power supply. The resolution of DPWM determines the control accuracy of the duty ratio signal, and in order to avoid the limit cycle phenomenon, the resolution of DPWM must be higher than that of ADC. Therefore, it is very important to design and realize high-resolution DPWM to improve the performance of digitally controlled switching power supply. However, for a high-resolution DPWM, the circuit structure is usually relatively complex, resulting in a large circuit area and power consumption of the DPWM, which...

AI Technical Summary

Problems solved by technology

However, since the delay chain in the DPWM structure is in an open-loop state and there is no closed-loop feedback adjustment mechanism, the delay time of the delay unit drifts with the chip manufacturing process, power supply voltage and operating temperature, resulting in a reduction in the conversion accuracy of DPWM

In addition, in order to implement a high-precision delay chain, a large area and power consumption overhead are required

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