A crystal oscillator circuit is connected between first and second oscillator pins of a chip and provides clock signals for the chip. The crystal oscillator circuit comprises a crystal, a first capacitor, a second capacitor and a third capacitor. The first capacitor is connected between the first and second oscillator pins of the chip. The second capacitor is connected between the first oscillator pin and ground. The third capacitor comprises one end connected to the second oscillator pin of the chip, and the other end grounded by way of the crystal.