Research And Design Of Current Detecting Circuit With High Precision And Wide Input Range

With the rapid development of semiconductor technology,the scale of integrated circuit is getting larger and larger,the circuit structure is getting more and more complex,the application is getting wider and wider,people's demand for integrated circuit is also getting higher and higher.The current detection circuit is one of the significant building blocks of integrated circuits.The traditional current detection circuit has the disadvantages of small current detection range and single output mode,and cannot cope with the increasingly complex working environment.Therefore,we need to improve the traditional current detection circuit,such as increasing the detection range of current,adding an analog-to-digital converter to convert analog to digital to achieve dual-mode output,and increasing the accuracy of current detection.Improve the performance of current detection circuit and adapt to complex working environment.Based on TSMC 0.18?m CMOS process standard,an integrated current detection circuit with high precision and input range is proposed.The active input structure is used to replace the traditional input structure to expand the current detection range whout increasing the input partial pressure,the high precision current mirror was designed to realize the current exact copy,and increase the precision of the current detection circuit.The 8-bit successive approximation analog-digital converter was designed to convert analog into digital quantity for dual mode output.At the same time,in order to increase the stability of the circuit and reduce the influence of the power supply voltage and temperature,a band-gap reference voltage source and a low-voltage differential linear regulator were designed to provide the bias voltage and energy supply voltage for the circuit.The design of the current mirror detection circuit was completed based on the TSMC 0.18?m CMOS process,and simulated by Spectre.The simulation results showed that:when the power voltage was 1.8V,the current detection range of the current detection circuit was 100nA-1mA,which span four orders of magnitude.The analog output error is less than 1%,the digital output is 8-bit binary code,and the maximum sampling rate is 312kHz,the maximum error is less than 3%.In the current detection circuit,the output voltage of the bandgap reference voltage source was 1.19V,the temperature coefficient was 28ppm/?,and the supply voltage rejection ratio was-86dB.The output voltage of the low-voltage differential linear voltage regulator was 1V,the temperature coefficient is 24ppm/?,and the supply voltage rejection ratio is-75dB.Based on TSMC 0.18pm CMOS process,the current detection circuit layout was completed,and the circuit layout verification and parameter extraction were completed by Calibre,and simulated by Spectre.The simulation results showed that:when the power voltage was 1.8 V,the current detection range of the current detection circuit was 100nA-1mA,which span four orders of magnitude.The analog output error is less than 1%,the digital output is 8-bit binary code,and the maximum sampling rate is 312kHz,the maximum error is less than 3%.In the current detection circuit,the output voltage of the bandgap reference voltage source is 1.19V,and the output voltage of the Low dropout linear regulator is 1V.