Patent ID: 9112448
Filing Date: 2015-08-18
Classification: H03B

Abstract:
1. An oscillator circuit to selectively switch between a normal mode and a low-power mode in response to a mode signal, the oscillator circuit comprising: a crystal to generate an oscillating signal; a first amplifier circuit to amplify the oscillating signal to generate, at a terminal of the crystal, a high-accuracy clock signal during the normal mode, the first amplifier circuit comprising: a second amplifier circuit to amplify the oscillating signal to generate, at the terminal of the crystal, a low-power clock signal during the low-power mode, the second amplifier circuit comprising: a switching circuit to selectively couple either the first amplifier circuit or the second amplifier circuit across the crystal in response to the mode signal; a first variable capacitor, coupled between a first node of the crystal and ground potential, including a control terminal responsive to the mode signal; and a second variable capacitor, coupled between a second node of the crystal and ground potential, including a control terminal responsive to the mode signal.