A Fully On-Chip, 6.66-Khz, 320-Na, 56 Ppm/Degrees C, Cmos Relaxation Oscillator With Pvt Variation Compensation Circuit

A fully on-chip CMOS relaxation oscillator (ROSC) with a PVT variation compensation circuit is proposed in this paper. The circuit is based on a conventional ROSC and has a distinctive feature in the compensation circuit that compensates for comparator's non-idealities caused by not only offset voltage, but also delay time. Measurement results demonstrated that the circuit can generate a stable clock frequency of 6.66 kHz. The current dissipation was 320 nA at 1.0-V power supply. The measured line regulation and temperature coefficient were 0.98%/V and 56 ppm/degrees C, respectively.