A Temperature- and Aging-Compensated RC Oscillator With ±1030-ppm Inaccuracy From40 °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 electromigration (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 ° C to 85 ° C after 500 h of accelerated aging at 125 ° C, with 5.1-
$\rm ps_{\mathrm{ rms}}$
period jitter and a power efficiency of 1.4
$\mu \text{W}$
/MHz.