A high-accuracy CMOS on-chip RC oscillator

In this paper, a high-accuracy CMOS on-chip RC oscillator (OSC) for MCU application is presented. The oscillator can provide a 16 MHz output frequency with the total accuracy in ±1% in all process corner at 1.8 v and 55°C condition, ±2% in all process, supply voltage and temperature condition after 7bit digital trimming. This design features low sensitivity to power supply from 1.8 v to 6.0 v and temperature range from -45°C to 85°C. The on-chip oscillator was fabricated in a 130 nm standard digital CMOS process. The final die size is 78 um×132 um.Experimental result shows that all performance satisfies the specification.