A Frequency-Configurable Oscillator Circuit Used in Switching Power Supply

Abstract

A frequency-configurable oscillator circuit applied to a switching power supply is used for generating a clock control signal and a ramp signal required by a switching power supply circuit and is an on-chip circuit. The frequency-configurable oscillator circuit includes a work module identification circuit, a delay circuit, a synchronization module, a charging current control circuit, and an internal oscillator. The oscillator can automatically generate corresponding control signals through the change of external configuration. The oscillator works in three different work modes which includes a fixed output frequency, an adjustable output frequency, and an external clock synchronization frequency. The oscillator circuit has simple configuration mode and high reliability, suits various configurable oscillator occasions, and satisfies different application demands.

Description

technical field [0001] The invention relates to an oscillator circuit applied to a switching power supply, in particular to an oscillator circuit with three operating modes and configurable frequencies, belonging to the technical field of digital-analog hybrid integrated circuits. Background technique [0002] The power supply is responsible for providing power guarantee for the normal work of various electronic devices. Currently commonly used power supplies are divided into linear regulated power supplies and switching regulated power supplies. The linear regulated power supply has the advantages of high stability, good reliability, and low cost, but it can only step down the voltage, has low energy efficiency, is bulky, and has a large volume. Compared with linear power supply, switching power supply has the following advantages: it can step up and step down, and has high power supply efficiency, but the control circuit and compensation circuit are more complicated. [...

AI Technical Summary

Problems solved by technology

Since the switching frequency of the switching power supply is closely related to the external inductor and capacitor, and needs to be 5 to 10 times the bandwidth of the internal loop, the fixed clock frequency limits the switching frequency of the switching power supply, which limits the scope of application of external devices and does not Facilitates internal loop stabilization by adjusting clock frequency

At the same time, with the application of the integrated system, the clock signal provided by the integrated system is more accurate and more stable when used in switching power supplies, while the traditional oscillator can only use the low-precision clock signal generated by itself, which lacks inheritance and flexibility sex

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