EP0352695A2 — Quartz crystal oscillator with temperature-compen…

Claim 1

Independent Claim 139 words

A temperature-compensated crystal oscillator, comprising: oscillating circuit means (1, 101), having a quartz crystal vibrator (3, 103) as an oscillating element, for oscillating at a predetermined frequency, said oscillating circuit means having frequency-temperature characteristics depending on a temperature, and the predetermined frequency being defined on the basis of the frequency-temperature characteristics; and temperature compensating means (10, 111, 112), coupled to said quartz crystal vibrator, for compensating the frequency-temperature characteristics of said oscillating circuit means, said temperature compensating means including, first temperature compensating means (11, 111) for compensating the frequency-temperature characteristics of said oscillating circuit means within a rated temperature range of said oscillating circuit means to obtain compensated frequency-temperature characteristics, and second temperature compensating means (12, 18, 112, 118) for further compensating frequency-temperature characteristics in a specific temperature region in the compensated frequency-temperature characteristics to obtain desired frequency-temperature characteristics.

Claim 2

Dependent Claim 139 words

A temperature-compensated crystal oscillator, comprising: oscillating circuit means (1, 101), having a quartz crystal vibrator (3, 103) as an oscillating element, for oscillating at a predetermined frequency, said oscillating circuit means having frequency-temperature characteristics depending on a temperature, and the predetermined frequency being defined on the basis of the frequency-temperature characteristics; and temperature compensating means (10, 111, 112), coupled to said quartz crystal vibrator, for compensating the frequency-temperature characteristics of said oscillating circuit means, said temperature compensating means including, first temperature compensating means (11, 111) for compensating the frequency-temperature characteristics of said oscillating circuit means within a rated temperature range of said oscillating circuit means to obtain compensated frequency-temperature characteristics, and second temperature compensating means (12, 18, 112, 118) for further compensating frequency-temperature characteristics in a specific temperature region in the compensated frequency-temperature characteristics to obtain desired frequency-temperature characteristics.

Claim 3

Dependent Claim 77 words

A temperature-compensated crystal oscillator according to claim 1, characterized in that said first temperature compensating means includes: a first compensation voltage generating circuit (13, 113) for generating a first compensation voltage corresponding to a temperature in the rated temperature range of said oscillating circuit means; and a first voltage variable capacitance element (14, 114), connected to said quartz crystal vibrator and said first compensation voltage generating circuit, for receiving the first compensation voltage to change a capacitance.

Claim 4

Dependent Claim 87 words

A temperature-compensated crystal oscillator according to claim 2, characterized in that said second temperature compensating means includes: a second compensation voltage generating circuit (15, 20) for generating a second compensation voltage corresponding to a temperature in the specific temperature region; and a second voltage variable capacitance element (16, 21), connected to said second compensation voltage generating circuit and said quartz crystal vibrator while being cut off from said first voltage variable capacitance element in a DC manner, for receiving the second compensation voltage to change a capacitance.

Claim 5

Dependent Claim 52 words

A temperature-compensated crystal oscillator according to claim 1, characterized in that said quartz crystal vibrator has first and second electrodes, said first electrode being connected to an electric circuit (4) in said oscillating circuit means, and said second electrode being connected to said first and second temperature compensating means (11, 12, 18).

Claim 6

Dependent Claim 53 words

A temperature-compensated crystal oscillator according to claim 3, characterized in that said quartz crystal vibrator has first and second electrodes, said first electrode being connected to an electric circuit (4) in said oscillating circuit means, and said second electrode being coupled to said first and second voltage variable capacitance elements (14, 16, 21).

Claim 7

Dependent Claim 100 words

A temperature-compensated crystal oscillator according to claim 1, characterized in that said quartz crystal vibrator includes at least first and second pairs of electrodes, said first pair of electrodes having first and second electrodes (131, 132), and said second pair of electrodes having third and fourth electrodes (133, 134), said first electrode is connected to an electric circuit (104) in said oscillating circuit means, and said second electrode is connected to said first temperature compensating means (111), and said third electrode is grounded through a capacitor and said fourth electrode is connected to said second temperature compensating means (112, 118).

Claim 8

Dependent Claim 75 words

A temperature-compensated crystal oscillator according to claim 6, characterized in that said first temperature compensating means includes: a first compensation voltage generating circuit (113) for generating a first compensation voltage corresponding to a temperature in the rated temperature range of said oscillating circuit means; and a first voltage variable capacitance element (114), connected to said quartz crystal vibrator and said first compensation voltage generating circuit, for receiving the first compensation voltage to change a capacitance.

Claim 9

Dependent Claim 72 words

A temperature-compensated crystal oscillator according to claim 7, characterized in that said second temperature compensating means includes: a second compensation voltage generating circuit (115, 120) for generating a second compensation voltage corresponding to a temperature in the specific temperature region; and a second voltage variable capacitance element (116, 121), connected to said quartz crystal vibrator and said second compensation voltage generating circuit, for receiving the second compensation voltage to change a capacitance.

Claim 10

Dependent Claim 175 words

A circuit for generating a voltage in correspondence with a temperature, comprising: first temperature sensing means (RT1), having a first resistance which changes in correspondence with first ambient temperature, for setting a first biasing voltage on the basis of the first resistance; first switching means (Tr1) for receiving the first biasing voltage to switch from an OFF state to an ON state at the first ambient temperature T1; second temperature sensing means (RT2), having a second resistance which changes in correspondence with second ambient temperature, for setting a second biasing voltage on the basis of the second resistance; second switching means (Tr2) for receiving the second biasing voltage to switch from an ON state to an OFF state at the second ambient temperature T2; and means (R1, R2, R3) for coupling said first and second switching means and causing said first and second switching means to perform a switching operation in a range defined by the first and second ambient temperatures T1 to T2 to generate a voltage corresponding to ambient temperature in the range.

Claim 11

Dependent Claim 175 words

A circuit for generating a voltage in correspondence with a temperature, comprising: first temperature sensing means (RT1), having a first resistance which changes in correspondence with first ambient temperature, for setting a first biasing voltage on the basis of the first resistance; first switching means (Tr1) for receiving the first biasing voltage to switch from an OFF state to an ON state at the first ambient temperature T1; second temperature sensing means (RT2), having a second resistance which changes in correspondence with second ambient temperature, for setting a second biasing voltage on the basis of the second resistance; second switching means (Tr2) for receiving the second biasing voltage to switch from an ON state to an OFF state at the second ambient temperature T2; and means (R1, R2, R3) for coupling said first and second switching means and causing said first and second switching means to perform a switching operation in a range defined by the first and second ambient temperatures T1 to T2 to generate a voltage corresponding to ambient temperature in the range.

Claim 12

Dependent Claim 198 words

A temperature compensating element for a quartz crystal oscillator, comprising: first temperature sensing means (RT1), having a first resistance which changes in correspondence with first ambient temperature, for setting a first biasing voltage on the basis of the first resistance; first switching means (Tr1) for receiving the first biasing voltage to switch from an OFF state to an ON state at the first ambient temperature T1; second temperature sensing means (RT2), having a second resistance which changes in correspondence with second ambient temperature, for setting a second biasing voltage on the basis of the second resistance; second switching means (Tr2) for receiving the second biasing voltage to switch from an ON state to an OFF state at the second ambient temperature T2; means (R1, R2, R3) for coupling said first and second switching means and causing said first and second switching means to perform a switching operation in a range defined by the first and second ambient temperatures T1 to T2 to generate a voltage corresponding to ambient temperature in the range; and voltage variable capacitance means (16, 21, 116, 121) for receiving a voltage corresponding to ambient temperature to change a capacitance in accordance with the voltage.

Claim 13

Dependent Claim 198 words

A temperature compensating element for a quartz crystal oscillator, comprising: first temperature sensing means (RT1), having a first resistance which changes in correspondence with first ambient temperature, for setting a first biasing voltage on the basis of the first resistance; first switching means (Tr1) for receiving the first biasing voltage to switch from an OFF state to an ON state at the first ambient temperature T1; second temperature sensing means (RT2), having a second resistance which changes in correspondence with second ambient temperature, for setting a second biasing voltage on the basis of the second resistance; second switching means (Tr2) for receiving the second biasing voltage to switch from an ON state to an OFF state at the second ambient temperature T2; means (R1, R2, R3) for coupling said first and second switching means and causing said first and second switching means to perform a switching operation in a range defined by the first and second ambient temperatures T1 to T2 to generate a voltage corresponding to ambient temperature in the range; and voltage variable capacitance means (16, 21, 116, 121) for receiving a voltage corresponding to ambient temperature to change a capacitance in accordance with the voltage.

Quartz crystal oscillator with temperature-compensated frequency characteristics

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag