一种超低功耗的低电压全金属氧化物半导体基准电压源

摘要

针对传统带隙基准电源电压高、功耗高和面积大的问题,提出了一种超低功耗的低电压全金属氧化物半导体(MOS)基准电压源.该基准源通过电压钳制使MOS管工作在深亚阈值区,利用亚阈值区MOS管的阈值电压差补偿热电势的温度特性,同时采用负反馈提高了电压源的线性度与电源抑制比.整个电压源电路采用SMIC 0.18 μm互补金属氧化物半导体工艺设计,仿真结果表明:基准电压源的电源电压范围可达0.5～3.3V,线性调整率为0.428％V-1,功耗最低仅为0.41 nW;在1.8V电源电压、-40～125℃温度范围内,温度系数为4.53×10-6℃-1,输出电压为230 mV;1 kHz下电源抑制比为-60 dB,芯片版图面积为625 tμm2.该基准电压源可满足植入式医疗、可穿戴设备和物联网等系统对芯片的低压低功耗要求.%A low-voltage all-metal oxide semiconductor (MOS) voltage reference with ultra-low power is presented to solve the problems of high supply voltage,high power consumption and large chip area in conventional band-gap references.The reference enforces all transistors to operate in the deep sub-threshold region through a voltage clamping technique,and the reference voltage is obtained by compensating the temperature characteristic of the thermal voltage with the difference of threshold voltages between two MOS transistors in sub-threshold region.Meanwhile,the linearity of the voltage reference and power supply rejection ratio are enhanced via negative feedback in the circuit,which is designed using the SMIC 0.18 μm complementary metal oxide semiconductor process.Simulation results show that the reference circuit is able to operate within 0.5-3.3 V voltage range of power supply with a linear regulation of 0.428％V-1,and the lowest power consumption is merely 0.41 nW.When the power supply voltage is 1.8 V in a temperature range from-40 to 125 ℃,the temperature coefficient is 4.53 × 10-6℃-1,the output voltage of the reference is 230 mV,and the power supply rejection ratio is-60 dB at 1 kHz frequency,while the layout area of the core circuit is only 625 μm2.The voltage reference can be used in the systems that require low voltage and low power consumption,such as implantable medical devices,wearable devices,and Internet of Things,etc.