Oscillating circuit and electronic device
OwnerMasaya Nohara, Takehito Ishii +1inventors
InventorsMasaya Nohara, Takehito Ishii, Noritoshi Kimura
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Abstract
An oscillation circuit which includes a Pierce circuit and a Colpitts circuit that share an oscillator and an input node to respective amplifiers and switches connected to output nodes of the respective amplifiers of the Pierce circuit and the Colpitts circuit. The switches are controlled to cause the oscillation circuit output oscillation signals of the Pierce circuit at the time of oscillation start-up and output oscillation signals of the Colpitts circuit at the time of steady-state oscillation.
Claims11
An oscillation circuit including an oscillator, the oscillation circuit comprising:
- a Pierce circuit and a Colpitts circuit that include a first amplifier and a second amplifier, respectively, and share the oscillator and an input node the first amplifier and the second amplifier;
- a first switch connected to an output node of the first amplifier, and
- a second switch connected to an output node of the second amplifier, wherein
- the first switch and the second switch are controlled to cause the oscillation circuit output oscillation signals of the Pierce circuit at the time of oscillation start-up and output oscillation signals of the Colpitts circuit at the time of steady-state oscillation.
An oscillation circuit comprising
- a Pierce circuit including include a first amplifier (A1) and a first oscillation capacitance (C1),
- a Colpitts circuit including a second amplifier (A2) and a second oscillation capacitance (C2),
- a first switch (SW1) connected in parallel to the first oscillation capacitance (C1) between an output of the first amplifier (A1) and the ground,
- a second switch (SW2) connected in parallel to the second oscillation capacitance (C2) between an output of the second amplifier (A2) and the ground,
- an oscillator (X1) between an input and an output of the first amplifier (A1), and
- a third oscillation capacitance (C3) between an input and an output of the second amplifier (A2), wherein
- he Pierce circuit and the Colpitts circuit share an input node to the first amplifier and the second amplifier,
- the first switch (SW1) is open and the second switch (SW2) is closed in a first mode at the time of oscillation start-up, and the first switch (SW1) is closed and the second switch (SW2) is open in a second mode at the time of steady-state oscillation.
Dependencies are inferred from the claim text.