A precisely-timed energy injection technique achieving 58/10/2μs start-up in 1.84/10/50MHz crystal oscillators

A fast start-up crystal oscillator using a preciselytimed energy injection technique is proposed. The prototype TSMC 65nm CMOS IC includes three different crystal oscillators, targeting 1.84MHz, 10MHz, and 50MHz frequencies with measured start-up times of 58μs, 10μs, and 2μs while consuming 6.7μW, 45.5μW, and 195μW respectively. This corresponds to 15x faster start-up over prior art. For each oscillator, two crystals with different package sizes and quality factors were tested to verify the technique's robustness over crystal's parameters and frequency variations.