Design And Research Of Low Voltage Temperature Sensor Integrated On Nano-CMOS Chip

As chip sizes continue to shrink,the issue of temperature protection inside high-performance chips has become a concern.At present,most SoC chips are designed with an on-chip integrated temperature sensor,which can protect the entire chip from being burned out without using too many resources,which has also become a new research hotspot.This paper analyzes the current status and development trend of the research on on-chip integrated temperature sensors in recent years.Two different types of temperature sensors are designed for different application scenarios:1)A low-power and small-size VCO temperature sensor is designed for an SoC over-temperature protection module.Using the positive temperature coefficient characteristic of the substrate PNP tube?V_BE in the CMOS process to generate a current I_PTATthat is positively related to absolute temperature,a“current starved”ring oscillator is designed based on this current,and the oscillator output frequency is proportional to the I_PTAT current.So that,the temperature inside the chip can be measured indirectly by detecting the frequency value.2)For an arithmetic chip,a high-precision and high-resolution ADC temperature sensor is designed.The substrate PNP tube is used to generate?V_BE and V_REF,and the second-order curvature compensation technique is used to eliminate the second-order nonlinear term of V_BE.The chopping technique can reduce mismatch and system errors.In terms of data processing,the structure of?V_BE and V_REF is used to achieve the conversion of temperature signal to time signal,and the low-speed and high-precision?-?ADC is used to output the temperature-dependent value?with high accuracy.The two designs in this paper use UMC28nm process,the power supply voltage is 0.9V and1.8V,the measurement temperature range is-40?125?,the linearity of FDC temperature sensor is 207?220kHz/?,the resolution is 12bit,and the total power consumption is less than 50uA.The resolution of ADC temperature sensor is 14bit,the average error is less than 1?,and the total power consumption is less than 200uA.