Design of a Novel CMOS Current Mode Bandgap Reference

A novel CMOS bandgap reference and an on-chip 3-bit trimming circuit is presented.The output reference voltage and current can be set to an a variable value,which can avoid employing an operarional amptifier and an off-chip precise resistor in the application.It also overcomes the systematic mismatch,output voltage bottom limitation and low PSRR of conventional current mode bandgap references.The proposed bandgap reference has been implemented in 0.5 μm CMOS mixed mode technology,the effect area is 450 μm×480 μm.The test results show that it has a 1.5 mW of power under the supply of 3 V,72 dB @ 1 kHz of PSRR,and temperature coefficient of 30×10-6V/°C from-40°C to 85°C.It has been used in the high speed high resolution ADC circuit.