A On-chip Supply Noise Detector In 55nm COMS Technology

On-chip power supply noise becomes more and more important with the development of modern technology.The dynamic changes of power supply cause uncertain changes in the critical path delay of digital circuits,causing circuit timing failures and functional errors.In addition,these transient changes may also affect the function of the digital-analog hybrid circuits.In order to solve these problems,real-time on-chip power detectors have become a common solution.The traditional method uses an external reference voltage,which is very sensitive to temperature changes.This paper proposes a complete set of real-time detection of power supply noise of the digital-analog hybrid system,the system is divided into coarse tuning and fine tuning two modules,when the coarse tuning module found power supply noise,start the fine tuning module to achieve more refined power supply noise monitoring.Coarse tuning is mainly composed of a time-to-digital converter(TDC)and a digital-analog hybrid adder(DAHA),in order to achieve the detection function of power supply noise of each module of the chip,it is distributed into each module of the chip,and its time detection accuracy can reach the picosecond level.The fine tuning module uses a feedback loop to adjust the voltage divider output to the calibration voltage,the voltage controlled oscillator(VCO)measures the calibration voltage and outputs the count value,and the count value of the number of oscillations of the VCO in the 200ns time window characterizes the calibration voltage,and the self-calibration method compensates for the effect of temperature on the VCO.The fine tuning circuit uses a 55nm CMOS process,can detect a voltage drop(IR-drop)of supply voltage of 0.9V to 1.2V,consumes 18μW to 66μW of 0.9V to 1.2V of supply voltage;has an area of272μm~2,has a detection accuracy of 0.24m V in a 200ns time window;and has a monitoring accuracy of 99.66%when the supply voltage of the circuit is 1.2V and its monitoring IR-drop changes to 120m V.The circuit monitors the maximum relative temperature error of power supply noise over a temperature range of-25℃to 125℃with a maximum relative temperature error of+2.3%and-1.6%.