Pulse width modulation (PWM) control direct current-direct current (DC-DC) converter

Abstract

The invention discloses a voltage feedback type pulse width modulation (PWM) control direct current-direct current (DC-DC) converter, which comprises a PWM control circuit, a driving circuit, a feedback loop, a power stage and a soft-starting circuit. The PWM control circuit realizes the conversion of an error signal from a voltage domain to a current domain and finally to a time domain by using a novel conversion circuit, and replaces an error amplifier and a comparator in the conventional structure, so that a polar point produced by a high-resistance output node of the error amplifier is eliminated, the stability of a loop is enhanced, the operation bandwidth of the circuit is expanded, and operating frequency is improved to reduce off-chip inductors and capacitors, so that system integration is facilitated. In addition, the operation of a transconductance amplifier is periodically controlled, so that the average static power consumption of the control circuit is lowered, and the efficiency of the converter is further improved. Moreover, a PWM control mode is realized under fixed frequency, so that the converter has high noise performance. The converter is applied to the fields of portable equipment, consumer electronics, radio frequency transceiver chips with high requirements on noise performance, and the like.

Description

technical field [0001] The invention belongs to the field of integrated circuit design and system application, and relates to a high-efficiency and low-noise DC-DC converter, in particular to a DC-DC converter adopting a PWM control mode. Background technique [0002] The power management module is a key circuit in chip design, which determines the working state of the entire chip. The DC-DC converter is a type of switching power supply, generally composed of a main circuit and a control circuit. The components that constitute the main circuit of the switching power supply include input power supply, switching tube, rectifier tube, energy storage inductor, filter capacitor and load, which together complete the conversion and transmission of electric energy, and are collectively called the power stage. The control circuit realizes the requirement of adjusting the output voltage to be constant at the set value by controlling the on-off of the power switch tube, so as to contro...

AI Technical Summary

Problems solved by technology

[0005] The PWM control method is to control the on and off of the power tube by adjusting the duty ratio of the pulse under the condition of a certain pulse frequency. Since the pulse frequency is fixed, the design difficulty of the off-chip LC filter network is reduced, and it has better noise performance. , however, in the light load state, due to the high operating frequency, the driving loss and the switching loss of the power tube dominate, which greatly reduces the working efficiency

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