Ultra-Low Power Crystal Oscillator With Adaptive Self-Start

摘要

A crystal oscillator is started in a high power mode for a certain period of time to ensure starting oscillation with average grade crystals, then once the certain time period is over the oscillator switches into a low power mode and sustains oscillation with energy pulses triggered by and synchronized with the oscillator output frequency. These energy pulses may be generated on the positive, negative or both positive and negative edges of the clock output waveform.

主权项

1. An integrated oscillator configured to be coupled with an external crystal, comprising:
an oscillator configured for a crystal to control an oscillation frequency thereof; a control circuit configured to operate in a first and a second mode, wherein at start-up of the oscillator the control circuit operates in the first mode and configures the oscillator to operate at a first power consumption, wherein the control circuit switches to the second mode after a certain time period of the oscillator oscillating; wherein when in the second mode the control circuit configures the oscillator to operate at a second power consumption which is less than the first power consumption; and oscillation is sustained during operation at the second power consumption by injecting pulses into the oscillator at rising and/or falling edges of an output signal from the oscillator.