A resistorless voltage reference source for 90 nm CMOS technology with low sensitivity to process and temperature variations

A new compact low power voltage reference source for wireless and embedded applications is described. The reference voltage source has been designed in a mixed-signal UMC 90 nm CMOS process using subthreshold characteristics for generating a constant voltage of 423 mV at supply voltages front 1.1 V to 3.3 V with total current consumption 270 nA. The proposed circuit occupies 0.001 mm(2) chip area and achieves less than 110 ppm/degrees C for all process corners and temperature variation from -40 degrees C to 125 degrees C. The power supply rejection ratio without any filtering capacitor at 100 Hz and 10 MHz is lower than -50 dB and -30 dB, respectively. The equivalent output voltage noise in the bandwidth from I Hz to 10 MHz reaches 218 mu V-RMS.