弛張式震盪器之分析與設計

Abstract

在切換式電源供應技術中，切換頻率大多設計在20K赫茲到2M赫茲範圍，在許多種類的震盪器中，弛張式震盪器能提供穩定並且容易控制的時脈訊號在20K赫茲到2M赫茲範圍內。 本論文著重在分析與設計弛張式震盪器，改善系統電容充放電切換方式，並且整合不同溫度係數的電路，減少溫度對頻率的影響，提高頻率的穩定性和系統效能，接著利用震盪器產生不同相位的時脈訊號，提供控制訊號於壓電變壓器系統，最後設計應用於切換式電源供應器系統之脈衝寬度調變器。

In the field of the switching mode power supply technology, switching frequency is normally designed between 20KHz and 2MHz. Among all the integrated-circuit oscillators, the relaxation oscillator provides a controllable and stable clock signal in the studied frequency range. This thesis focuses on analyzing and designing the relaxation oscillator. A new charging and discharging circuit presented to improve the characteristic of capacitor voltage. The circuits with different temperature coefficient are used to minimize the temperature effect on the clock signal. The performance and stability of the clock system are improved. The designed relaxation oscillator is slightly amended to generate clock signal with controlled phase, which are utilized for controlling piezo transformer systems. Also, a pulse-width modulation is implemented using the presented oscillator.