Clock signal generation circuit, detection device, sensor, electronic apparatus, and moving object

Patent metadata

Field	Value
Publication number	US-9391595-B2
Application number	US-201414552979-A
Country	US
Kind code	B2
Filing date	Nov 25, 2014
Priority date	Nov 27, 2013
Publication date	Jul 12, 2016
Grant date	Jul 12, 2016

Abstract

A clock signal generation circuit includes a CR oscillator circuit having a capacitor, a resistor, and an amplifier circuit, and a voltage generation circuit adapted to generate a power supply voltage, and then supply the CR oscillator circuit 170 with the power supply voltage VDOS. An oscillation frequency of the CR oscillator circuit in a case in which a power supply voltage VDDL is a fixed voltage has a positive temperature characteristic. The voltage generation circuit generates the power supply voltage VDOS having a negative temperature characteristic based on a work function difference between transistors, and then supplies the power supply voltage VDOS as a power of the amplifier circuit of the CR oscillator circuit.

First claim

What is claimed is:

1. A clock signal generation circuit comprising:
a CR oscillator circuit including a capacitor, a first resistor, and an amplifier circuit; and
a voltage generation circuit adapted to generate a power supply voltage, and supply the CR oscillator circuit with the power supply voltage, wherein the voltage generation circuit includes a first transistor, a second transistor, and a second resistor, a gate electrode of the second transistor has a conductivity that is different from that of the first transistor, and the second resistor receives a voltage based on a work function difference between the first transistor and the second transistor, further wherein:
an oscillation frequency of the CR oscillator circuit in a case in which the power supply voltage is a fixed voltage has a positive temperature characteristic, and
the voltage generation circuit generates the power supply voltage having a negative temperature characteristic based on a work function difference between the first transistor and the second transistor, and supplies the power supply voltage as a power for the amplifier circuit of the CR oscillator circuit.

2. The clock signal generation circuit according to claim 1 , wherein
the first resistor includes
a plurality of resistor elements and a reference resistor element connected in series to each other,
a plurality of fuse elements disposed corresponding respectively to the resistor elements in parallel to the corresponding resistor elements, and
a trimming auxiliary switch disposed in parallel to the reference resistor element, set to an OFF state in a first measurement mode of an oscillation frequency before cutting the fuse element, and set to an ON state in a second measurement mode of the oscillation frequency before cutting the fuse element.

3. An electronic apparatus comprising:
the clock signal generation circuit according to claim 2 ; and
a display section that displays information.

4. A moving object comprising:
the clock signal generation circuit according to claim 2 ; and
a drive mechanism to provide a drive force.

5. An electronic apparatus comprising:
the clock signal generation circuit according to claim 1 ; and
a display section that displays information.

6. A moving object comprising:
the clock signal generation circuit according to claim 1 ; and
a drive mechanism to provide a drive force.

7. A detection device comprising:
a clock signal generation circuit that includes:
a CR oscillator circuit including a capacitor, a resistor, and an amplifier circuit, and
a voltage generation circuit adapted to generate a power supply voltage, and supply the CR oscillator circuit with the power supply voltage, wherein an oscillation frequency of the CR oscillator circuit in a case in which the power supply voltage is a fixed voltage has a positive temperature characteristic, and the voltage generation circuit generates the power supply voltage having a negative temperature characteristic based on a work function difference between transistors, and supplies the power supply voltage as a power for the amplifier circuit of the CR oscillator circuit;

a drive circuit adapted to receive a feedback signal from a physical quantity transducer and drive the physical quantity transducer;
a detection circuit adapted to receive a detection signal from the physical quantity transducer to detect a desired signal; and
a control section adapted to receive the clock signal from the clock signal generation circuit, and control the drive circuit and the detection circuit.

8. The detection device according to claim 7 , wherein
the clock signal generation circuit is set to an operation enable state by releasing a power-on reset state, and supplies the control section with the clock signal, and
the control section having started an operation due to the supply of the clock signal starts up the drive circuit and the detection circuit.

9. A detection device comprising:
a clock signal generation circuit adapted to generate a clock signal using a CR oscillator circuit;
a drive circuit adapted to receive a feedback signal from a physical quantity transducer and drive the physical quantity transducer;
a detection circuit adapted to receive a detection signal from the physical quantity transducer to detect a desired signal; and
a control section adapted to receive the clock signal from the clock signal generation circuit, and control the drive circuit and the detection circuit,
wherein the CR oscillator circuit operates being supplied with a power supply voltage having a negative temperature characteristic,
the clock signal generation circuit is set to an operation enable state by releasing a power-on reset state, and supplies the control section with the clock signal, and
the control section having started an operation due to the supply of the clock signal starts up the drive circuit and the detection circuit.

10. The detection device according to claim 7 , wherein
the physical quantity transducer is a vibrator,
the drive circuit includes
an amplifier circuit adapted to amplify the feedback signal,
a drive signal output circuit adapted to output a drive signal of the vibrator,
a gain control circuit adapted to control an amplitude of the drive signal, and
a high-pass filter disposed between the amplifier circuit and the drive signal output circuit, and

the clock signal from the clock signal generation circuit is input to the drive signal output circuit via a resistor element constituting the high-pass filter in a start-up period of an oscillation of the vibrator.

11. The detection device according to claim 7 , further comprising:
a second drive circuit adapted to receive a second feedback signal from a second physical quantity transducer, and drive the second physical quantity transducer; and
a second detection circuit adapted to receive a second detection signal from the second physical quantity transducer to detect a desired signal,
wherein the detection circuit includes a first A/D converter circuit,
the second detection circuit includes a second A/D converter circuit, and
the first A/D converter circuit and the second A/D converter circuit each convert an analog signal into a digital signal based on the clock signal from the clock signal generation circuit.

12. The detection device according to claim 11 , wherein
the control section includes a digital signal processing section adapted to receive the digital signals from the first A/D converter circuit and the second A/D converter circuit, and perform digital signal processing on the digital signals, and
the digital signal processing section adapted to perform the digital signal processing based on the clock signal from the clock signal generation circuit.

13. The detection device according to claim 11 , wherein
the physical quantity transducer is a vibrator adapted to detect a rotational angular velocity around a first axis,
the second physical quantity transducer is a second vibrator adapted to detect a rotational angular velocity around a second axis, and
the vibrator vibrates at a first frequency, and the second vibrator vibrates at a second frequency different from the first frequency.

14. A sensor comprising:
the detection device according to claim 7 ; and
a physical quantity transducer.

15. The detection device according to claim 7 , further comprising:
a power supply terminal to which an external power supply voltage is input; and
a regulator circuit adapted to perform a voltage adjustment of stepping down the external power supply voltage from the power supply termin

Assignees

• Seiko Epson Corp

Inventors

• Higuchi Teppei
• Tanaka Masafumi
• Maki Katsuhiko

Classifications

• H03K3/03 Primary

  Astable circuits · CPC title

• H03K3/011

  Modifications of generator to compensate for variations in physical values, e.g. voltage, temperature {(to maintain energy constant H03K3/015)} · CPC title