雙載子電晶體直流同步降壓控制器設計

BIPOLAR SYNCHRONOUS DC-DC BUCK CONVERTER DESIGN

黃建中(Chien-Chung Huang)

指導教授 ： 黃淑絹

大同大學/電機資訊學院/電機工程學系所/碩士(2009年)

摘要

本論文設計一個直流同步降壓型轉換器，並且採用40V的雙載子電晶體製程來模擬。整個電路主要使用的是電壓模式的PWM直流電壓轉換器操作電壓在+4.3V到20V之間。模擬的結果顯示內部振盪器的震盪頻率為200 kHz。藉由底端N-MOSFET的RDS (ON)，我們可以建立一個電流限制的保護機制。柔性啟動功能可以保護開機瞬間，因為突波的大電流所造成的損壞。過熱保護機制可以在溫度超過攝氏150度時，保護整個系統。

關鍵字

同步降壓控制器

並列摘要

A DC-DC synchronous buck converter with soft start has been designed and simulated with 40V bipolar process. The overall circuit is designed based on a voltage-mode PWM controlled converter. The input voltage range is from +4.3V to +20V. Simulation results show that this converter with on-chip current sensor can operate at 200 kHz. The current limit is implemented by sensing the voltage drop across the bottom N-MOSFET RDS (ON). The soft start function is used to prevent large inrush currents upon power-up. The internal thermal protection circuit can protect the system when the temperatures exceed 150°C.

並列關鍵字

synchronous step-down converter

參考文獻

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