Patent ID: 6215370
Filing Date: 2001-04-10
Classification: H03B,H03K

Abstract:
A crystal oscillator circuit for producing oscillations at an overtone frequency comprising:a CMOS invertor having an input terminal and an output terminal;a crystal resonator, configured for overtone oscillation at the overtone frequency, connected between the input terminal and the output terminal respectively at a first connection node and a second connection node;a feedback resistor connected between the input terminal and the output terminal of the CMOS invertor;a first capacitor provided between the first connection node and a power source terminal at a predetermined potential;a second capacitor provided between the second connection node and a power source terminal at the predetermined potential; andat least one fixed resistor disposed in series with at least one of the first capacitor and the second capacitor and having a resistance limiting a crystal current in the crystal resonator and maintaining negative circuit resistance for stable oscillation at the overtone frequency of the crystal resonator.