Crystal oscillator
First Claim
1. A crystal oscillator that generates an output oscillating signal by a crystal, the crystal oscillator comprising:
- a first pad and a second pad, coupled to two nodes of the crystal;
an amplifier, coupled to the first pad, for amplifying a crystal oscillating signal received from the first pad and generating an amplifying signal, wherein the amplifier comprises;
a first transistor, having a first gate for receiving the crystal oscillating signal, having a first source coupled to a first operating voltage;
a second transistor, having a second drain coupled to a first drain of the first transistor, having a second source coupled to a second operating voltage;
a third transistor, having a third gate coupled to a second gate of the second transistor, having a third source coupled to the second operating voltage; and
a fourth transistor, having a fourth drain coupled to a third drain of the third transistor, having a fourth source coupled to the first operating voltage, wherein the second and the third transistors form a current mirror circuit, wherein the first and the fourth transistors are implemented by NMOS transistors and the second and the third transistors are implemented by PMOS transistors; and
an inverter, coupled to the amplifier, for inverting the amplifying signal and generating the output oscillating signal,wherein the amplifier has a first power consumption, the inverter has a second power consumption, and the first power consumption is smaller than the second power consumption.
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Accused Products
Abstract
This invention discloses a crystal oscillator, in which by appropriately designing the gain of an amplifier to achieve high trans-conductance and low power consumption. This crystal oscillator includes a first pad, coupled to a first node of a crystal, for receiving a crystal oscillating signal outputted from the crystal; an amplifier, coupled to the first pad, for amplifying the crystal oscillating signal to generate an amplifying signal; an inverter, coupled to the amplifier, for inverting the amplifying signal; and a second pad, coupled to a second node of the crystal, for outputting an oscillating signal to the crystal.
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Citations
15 Claims
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1. A crystal oscillator that generates an output oscillating signal by a crystal, the crystal oscillator comprising:
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a first pad and a second pad, coupled to two nodes of the crystal; an amplifier, coupled to the first pad, for amplifying a crystal oscillating signal received from the first pad and generating an amplifying signal, wherein the amplifier comprises; a first transistor, having a first gate for receiving the crystal oscillating signal, having a first source coupled to a first operating voltage; a second transistor, having a second drain coupled to a first drain of the first transistor, having a second source coupled to a second operating voltage; a third transistor, having a third gate coupled to a second gate of the second transistor, having a third source coupled to the second operating voltage; and a fourth transistor, having a fourth drain coupled to a third drain of the third transistor, having a fourth source coupled to the first operating voltage, wherein the second and the third transistors form a current mirror circuit, wherein the first and the fourth transistors are implemented by NMOS transistors and the second and the third transistors are implemented by PMOS transistors; and an inverter, coupled to the amplifier, for inverting the amplifying signal and generating the output oscillating signal, wherein the amplifier has a first power consumption, the inverter has a second power consumption, and the first power consumption is smaller than the second power consumption. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A crystal oscillator that generates an output oscillating signal by a crystal, the crystal oscillator comprising:
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a first pad and a second pad, coupled to two nodes of the crystal; an amplifier, coupled to the first pad, for amplifying a crystal oscillating signal received form the first pad and generating an amplifying signal, wherein the amplifier comprises; a first transistor, having a first gate for receiving the crystal oscillating signal, having a first source coupled to a first operating voltage; a second transistor, having a second drain coupled to a first drain of the first transistor, having a second source coupled to a second operating voltage; a third transistor, having a third gate coupled to a second gate of the second transistor, having a third source coupled to the second operating voltage; and a fourth transistor, having a fourth drain coupled to a third drain of the third transistor, having a fourth source coupled to the first operating voltage, wherein the second and the third transistors form a current mirror circuit; and an inverter, coupled to the amplifier, for inverting the amplifying signal and generating the output oscillating signal; wherein the amplifier has a first power consumption, the inverter has a second power consumption, and the first power consumption is smaller than the second power consumption, wherein the second gate of the second transistor is used as a first output terminal of the amplifier, and outputs a first amplifying signal to the inverter, and a fourth gate of the fourth transistor is used as a second output terminal of the amplifier, and outputs a second amplifying signal to the inverter. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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Specification