【摘要】 设计了一种用于降压型DC-DC开关电源转换器的锯齿波振荡器。利用电压前馈方法和固定充放电时间方法,实现了锯齿波幅度随电源电压线性变化且频率固定的锯齿波振荡器,抑制了电源电压突变时的输出电压过冲。基于0.18μm BCD工艺进行设计和仿真。仿真结果表明,该锯齿波振荡器产生的锯齿波频率为2.73MHz。在2.7～5.5V电源电压、-55℃～125℃温度范围内,频率偏移在±6%以内。振荡幅度在0.576～1.470V范围内随电源电压线性变化。更多还原

【Abstract】 A saw-tooth wave oscillator was designed for buck DC-DC converters.Voltage feed-forward and fixed charge and discharge time techniques were used to keep the amplitude of saw-tooth wave changing linearly and the frequency of saw-tooth wave constant while the supply voltage was changed.Therefore,the overshoot voltage was suppressed when the supply voltage was changed suddenly.Based on a 0.18μm BCD process,the saw-tooth wave oscillator was designed and simulated.Simulation results showed that the frequency of the designed saw-tooth wave oscillator was 2.73 MHz.In the range of supply voltage from 2.7 Vto 5.5 Vand temperature from-55℃to 125℃,the variation of frequency was within ±6%.The oscillating amplitude was changed linearly from 0.576 Vto1.470 Vfollowing the supply voltage.更多还原