A Temperature- and Aging-Compensated RC Oscillator With 1030-ppm Inaccuracy From-40 C to 85 C After Accelerated Aging for 500 h at 125 C

This article presents a temperature- and aging-compensated RC oscillator (TACO) in which the long-term drift of the main oscillator is compensated by periodically locking its frequency to that of the less-aged reference oscillator. To improve the long-term stability of the TACO, it employs techniques, such as the use of higher activation energy (E-a) resistors, switched dual RC branches to mitigate stress from dc-current-induced electro migration (EM), and duty cycling to slow down the aging rate of the reference oscillator. Using the proposed techniques, a prototype 100-MHz RC oscillator fabricated in a 65-nm CMOS process achieves an inaccuracy of +/- 1030 ppm from -40 degrees C to 85 degrees C after 500 h of accelerated aging at 125 degrees C, with 5.1-ps(rms) period jitter and a power efficiency of 1.4 mu W/MHz.