A CMOS Voltage Reference Combining Body Effect with Switched-Current Technique

A precise CMOS voltage reference using body effect and switched-current technique is presented in this paper. To reduce static current, the threshold voltage with body effect in nMOSFET transistor is utilized instead of the VBE of BJT transistor. Owning to the switched-current technique, only one transistor is required to generate the reference voltage, so that the threshold voltage mismatch in conventional two-transistor configuration is eliminated. The proposed circuit is designed and simulated under 0.18-mu m CMOS technology. The output voltage is 147.44 mV, and the temperature coefficient is less than 5.2 ppm/degrees C ranging from -20 degrees C to 100 degrees C. The voltage line-sensitivity is 0.44 %/V ranging from 1.5 V to 3.3 V. The power-supply- rejection-ratio (PSRR) is -56 dB at 100 Hz. The average current consumption is about 16 mu A.