一种基于标准CMOS工艺的低成本振荡器的设计

Design of Low Cost Ring Oscillator Based on Standard CMOS Process

提出了一种基于标准CMOS工艺的低成本环形补偿振荡器。由于采用了误差反馈补偿技术，该振荡器无需精准的电流源和电压源；利用电阻温度补偿和电源电压稳压，使振荡周期对温度、电压，以及工艺偏差均有较强的容忍能力，且周期大小易于调整。在输入电压范围为4．5～6V，温度范围-40～125℃，以及五个MOSFET工艺偏差的情况下，进行了Hspice仿真。结果表明，在最坏情况下，振荡器周期的最大偏差为7．5％，而在不考虑温度的情况下，由电压和MOSFET工艺变化所引入的振荡周期偏差为0．9％。该振荡器满足电源管理芯片要求，适合低成本DC／DC转换器、充电器等电源管理芯片的应用。

A low cost ring oscillator with compensation is proposed based on standard CMOS process. Error feedback compensation technology were used in the circuit, which eliminates the need for precise current and voltage references. And the tolerance of oscillation cycle to variations in temperature, voltage and process was significantly improved by using resistor temperature compensation and supply voltage regulation. Furthermore, the oscillation cycle was ready to tune. The circuit was simulated with Hspice under all MOS corners within the voltage and temperature range from 4. 5 V to 6 V and -40 ℃ to -125 ℃, respectively. Results indicated that the maximum combined cycle variation was 7. 5% under the worst case, and the variation was only 0. 9% without considering temperature variations. The oscillator is suitable for application in low cost power management IC＇ s, such as DC/DC converter and charger.