A novel on-chip oscillator with temperature self-calibrationwasdesigned for digital power. The oscillator used ring oscillator on chip as a "temperature sensor", the offset current of ring oscillator was designed to be proportionalto thermodynamic temperature. As a reference signal for calibration, the frequency of the output clock signalwas highly sensitive to temperature. The self-calibration algorithm controlled the current of RC oscillator and calibrated the output clock frequency, which completed real-time temperature self-calibration function. The symmetric structure of two comparator and SRtrigger was adopted to reduce the delay error. Based on 0.18μm BCD process, the circuit was simulated by using Cadence and Hspice software. The simulation results show that the center frequency is 10.1MHz, and the offset of oscillator frequency withtemperature variation is within±0.6% when the temperature rangesin-55-+155℃.%设计了一种应用于数字电源的新型温度自校准高精度片上振荡器.该振荡器利用片内集成的环形振荡器作为"温度传感器",环形振荡器的偏置电流设计成与热力学温度成正比,输出时钟信号频率对温度变化高度敏感,以此作为温度校准的参考信号,经过数字自校准算法产生控制RC振荡器充电电流大小的信号,校准RC振荡器输出时钟频率,从而完成片上实时温度自校准的功能.采用双比较器加SR触发器对称结构,降低比较器延迟误差.电路基于0.18μm BCD工艺模型,采用Cadence和Hspice进行仿真.仿真结果表明,在-55~+155℃温度范围内,振荡器输出中心频率为10.1 MHz,振荡器的频率随温度变化的偏移量在±0.6%以内.
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