Oscillation circuit and electronic device
First Claim
1. An oscillation circuit comprising:
- a differential amplifier having a plurality of output terminals providing output signals having different phases from each other;
a piezoelectric resonator; and
a phase shift circuit transmitting output signals that result from a predetermined phase shift of input signals;
wherein the differential amplifier, piezoelectric resonator, and phase shift circuit form a positive feedback oscillation loop; and
wherein a signal selection part for selecting one of the output terminals of the differential amplifier is provided, the positive feedback oscillation loop being completed with one of the output terminals of the differential amplifier.
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Accused Products
Abstract
An oscillation circuit 30 comprises a differential amplifier 31 having plural output terminals that provide output signals having different phases from each other, a SAW resonator 32, and a phase shift circuit 35, wherein the differential amplifier 31, SAW resonator 32, and phase shift circuit 35 forming a positive feedback oscillation loop and a switch circuit 34 being provided for selecting one of the output terminals of the differential amplifier 31 to complete the positive feedback oscillation loop. The switch circuit 34 selects one of the signals SQ1 and SQ2 and transmits it to the phase shift circuit 35. The phase shift circuit 35 transmits output signals that result from a predetermined phase shift of input signals to the SAW resonator 32.
11 Citations
29 Claims
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1. An oscillation circuit comprising:
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a differential amplifier having a plurality of output terminals providing output signals having different phases from each other;
a piezoelectric resonator; and
a phase shift circuit transmitting output signals that result from a predetermined phase shift of input signals;
wherein the differential amplifier, piezoelectric resonator, and phase shift circuit form a positive feedback oscillation loop; and
wherein a signal selection part for selecting one of the output terminals of the differential amplifier is provided, the positive feedback oscillation loop being completed with one of the output terminals of the differential amplifier. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
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2. An oscillation circuit comprising:
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a differential amplifier having a plurality of output terminals providing output signals having different phases from each other;
a piezoelectric filter; and
a phase shift circuit transmitting output signals that result from a predetermined phase shift of input signals;
wherein the differential amplifier, piezoelectric filter, and phase shift circuit form a positive feedback oscillation loop; and
wherein a signal selection part for selecting one of the output terminals of the differential amplifier is provided, the positive feedback oscillation loop being completed with one of the output terminals of the differential amplifier.
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Specification