一种用于DC-DC开关稳压器的锯齿波振荡器设计

Design of Sawtooth Wave Oscillator for DC-DC Switching Regulator

由于开关稳压器功耗低、体积小的特点,在各种电子设备中得到广泛应用。锯齿波振荡器是开关稳压器中的一个重要组成部分,其决定着开关稳压器占空比的精度,一个不准确的占空比将给最终输出带来误差。通过使用两个三角波合成锯齿波的方式设计了一种新型锯齿波振荡器,与常用的锯齿波振荡器相比,能够有效减小锯齿波信号下降时间、振幅误差以及频率误差,已成功应用于一款DC-DC降压开关电源芯片。

The switch regulator is widely used in various electronic equipments because of its low power consumption and small size.Sawtooth wave generator is an important component of switching regulator.It determines the precision of the duty cycle of the switching regulator.An inaccurate duty cycle will bring error to the final output.In this paper,a new sawtooth wave oscillator is proposed by using two triangle wave to synthesize sawtooth wave.It can effectively reduce fall time,amplitude error and frequency error of sawtooth wave signal compared to the commonly used sawtooth wave oscillators.The oscillator has been successfully applied to a DC-DCbuck switching power supplychip.