论文部分内容阅读
基于0.25μm BCD工艺,设计了一种应用于开关电源的多模式环形振荡器,具有结构简单、三种模式可选、可修调的特点。电路通过模式切换生成可调电流的方式对电容充放电,产生不同频率的斜坡及方波信号。测试结果表明:在-40℃~125℃温度范围内,振荡器主振荡模式输出范围为483.9~518.6kHz,与固定频率(500kHz)的最大偏移率为3.72%,电阻频率调节模式输出范围为25kHz~2.5 MHz,同步模式下可调同步频率范围为40kHz~4 MHz。目前,该振荡器已被成功应用于一种DC-DC开关电源芯片中。
Based on the 0.25μm BCD process, a multi-mode ring oscillator for switching power supply is designed. It has the advantages of simple structure, three modes selectable and adjustable. Circuit through the mode switch to generate adjustable current charging and discharging of the capacitor, resulting in different frequency of the ramp and square wave signal. The test results show that the output range of oscillator main oscillation mode is from 483.9 to 518.6kHz and the maximum deviation from fixed frequency (500kHz) is 3.72% in the temperature range from -40 ℃ to 125 ℃. The output range of resistance frequency adjustment mode is 25kHz ~ 2.5MHz, synchronous mode adjustable synchronous frequency range of 40kHz ~ 4MHz. At present, the oscillator has been successfully applied to a DC-DC switching power supply chip.