Synchronous rectification step-down converter chip with high-precision current detection function

Abstract

The invention belongs to the field of power management and relates to a DC-DC step-down converter, in particular to a synchronous rectification step-down converter chip with a high-precision current detection function. The chip is based on a current PWM-mode DC-DC step-down converter. In the chip, the synchronous rectification switch PWM-mode current control technology is adopted, so the efficiency of the converter is greatly improved, and the output current can reach 2 A. By the adoption of a novel current detection sensing module with extremely high precision, the magnitude of a current can be detected more accurately in time, and the chip can be subjected to reliable overcurrent protection. Besides, according to the design of the chip, a double-frequency oscillator is adopted, so the frequency of a switching tube can be selected automatically according to the load capacity, the efficiency of the chip can be improved, and the working time of the chip can be prolonged. Lastly, the chip integrates a soft start circuit, so a surge current and an overshoot voltage which are generated during start can be suppressed, and an LED lamp and a driving chip can be protected against damage.

Description

[0001] technical field [0002] The invention belongs to the field of power supply management, relates to a DC-DC step-down converter, in particular to the design of a step-down converter circuit with a high-precision current detection circuit. Background technique [0003] Power supply is an indispensable part of various electronic equipment, and its performance is directly related to the technical indicators of electronic equipment and whether it can work safely and reliably. Whether it is the most advanced personal computer, communication equipment or automotive electronics, whether it can achieve efficient and intelligent power management will have a significant impact on the performance of the entire system. In recent years, the portable consumer electronic equipment market has grown rapidly, and user demands have continued to increase. The increasingly rich functions such as audio and video, data input, and wireless connections in smart phones and portable devices have...

AI Technical Summary

Problems solved by technology

Portable electronic products are usually powered by batteries. As the discharge progresses, the battery voltage gradually decreases and the internal resistance of the battery gradually increases: On the one hand, when the battery starts to be used, the terminal voltage is high and the internal resistance of the battery is small, which easily causes the output current The current greater than the actual demand of the load will cause waste of electric energy, especially not conducive to the extension of the system working time and standby time; on the other hand, after a period of use, the terminal voltage decreases and the internal resistance of the battery increases, resulting in a large power supply caused by load changes Voltage changes are not conducive to the system to maintain high-performance work

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