JPH10290119A - Oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten time for start and to reduce power consumption in the case of continuous oscillation by providing an oscillation detection circuit for detecting the operation of oscillation circuit, switching means to be operated based on the output of oscillation detection circuit, and constant voltage circuit for supplying voltages higher than two of high and low values at least. SOLUTION: When oscillation is stopped, an oscillation detection circuit 3 detects such a state, outputs a logic signal 3a at high level, turns on an analog switch 4 and supplies a high voltage V1 to an oscillation circuit 2. When the oscillation circuit 2 is triggered by applying a trigger signal from an external system, since the high voltage V1 is supplied to the oscillation circuit 2, the oscillation circuit 2 is started in an extremely short time. When a stationary oscillation output is attained after start, the oscillation detection circuit 3 detects such a state and outputs the logic signal 3a at low level. According to this logic signal 3a, the analog switch 4 is turned off, the supply of high voltage V1 is cut off and a low voltage V2 is impressed through an analog switch 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an oscillation device,
In particular, the present invention relates to an oscillation device to which an oscillation oscillator is applied.

[0002]

2. Description of the Related Art Some oscillating devices to which an oscillating oscillator such as a crystal oscillator can be externally attached are incorporated in, for example, a microprocessor having a clock function. Devices incorporating such an oscillation device are desired to be small and lightweight as portable devices, and furthermore, for example, because a battery power supply is mainly used,
It is required to operate for a long time with low power consumption.
As an attempt to reduce the power consumption of the oscillation device, a configuration has been proposed in which steady oscillation after oscillation startup is maintained at a low voltage or low current.

FIG. 3 shows an example of a conventional oscillating device for realizing such low power consumption.
FIG. 43 is a block diagram of a configuration disclosed in Japanese Patent Publication No. 43-43.
As shown in the figure, the oscillation device OS100 uses a battery 101 that supplies power to each circuit as a power source, and the output of the battery 101 is connected to a voltage conversion circuit 102 such as a DC / DC converter. The voltage conversion circuit 102 outputs a constant voltage at all times or at a predetermined timing. This output voltage is supplied to a constant voltage circuit 104 which outputs a predetermined voltage through a capacitor 103, and a timer circuit 10
6. The oscillation circuit 105 is provided with an analog switch 10 operated by the output of the timer circuit 106.
7, or the output of the timer circuit 106 is
09 operating through the analog switch 108
Either the output of the voltage conversion circuit 102 or the output of the constant voltage circuit 104 is supplied.

When a battery 101 is loaded (or power is turned on) into the oscillation device OS100, power is supplied to a voltage conversion circuit 102, and the voltage conversion circuit 102 outputs a predetermined voltage. Then, the timer circuit 106 starts operating. At this time, the H level is output from the timer circuit 106. The H level is input to the analog switch 107 and turned on, and the L level is input to the analog switch 108 that operates via the inverter 109 and turned off. That is,
A relatively high voltage output from the voltage conversion circuit 102 is supplied to the oscillation circuit 105, and the oscillation circuit 105 is activated.

After a lapse of a predetermined time from the start, the L level is output from the timer circuit 106. Then, the L level is input to the analog switch 107 to be turned off, and the analog switch 108 that operates via the inverter 109 is turned off. Is turned on by inputting the H level. Accordingly, a relatively low voltage output Vreg by the constant voltage circuit 104 is supplied to the oscillation circuit 105, and the oscillation circuit 10
5 will continue to operate.

That is, Vbat is the output of the battery 101,
VDD is the voltage supplied to each circuit at the output of the voltage conversion circuit 102, VDD1 is the input of the oscillation circuit 105, Xout is the output of the oscillation circuit 105, Vreg is the output of the constant voltage circuit 104, and Tout is the output of the timer circuit 106. Then V
VDD and Vreg are output almost simultaneously with the bat output,
H level is output to Tout. In addition, VDD is output to VDD1, and oscillation with an amplitude of VDD is output to Xout with a time lag.

When a predetermined time elapses in this state, Tou
t level is output, and at the same time, VDD1 is Vre
g is supplied, and oscillation is output to Xout with an amplitude of Vreg. In this way, a relatively high voltage is supplied at the time of startup to smoothly start the oscillation, and in the steady oscillation after a lapse of a predetermined time measured by the timer after the startup, the supply voltage is switched to a relatively low voltage to reduce power consumption. Is to be reduced.

[0008]

However, a device having a built-in oscillation circuit is not provided with a configuration for continuously oscillating as described above, but for example at a predetermined time and for a predetermined period. Oscillation is performed, and then oscillation is stopped to save power. In such a configuration, oscillation is started intermittently, and after a certain period of time after starting,
Alternatively, after a predetermined operation is completed, the oscillation is stopped, and such a cycle is repeated.

On the other hand, the conventional oscillating device having the above-mentioned configuration is not always suitable for applications in which start and stop of oscillation are repeated irregularly or regularly. Further, for example, when an unexpected voltage drop or the like occurs for some reason and the oscillation is temporarily stopped, in the conventional oscillation device having the above-described configuration, it is necessary to reset the timer circuit and the like again at the time of the recovery operation, There is a disadvantage that it takes an overhead time for this. In addition, it is necessary to additionally provide a reset routine built-in and a means for executing the reset routine, thereby increasing the number of parts, resulting in an increase in equipment cost, and an extra circuit / equipment for operating the extra circuit / equipment itself. The conventional configuration was not advantageous because of disadvantages such as power consumption.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in the prior art, and it is intended to repeatedly oscillate /
Suitable for equipment with a stop cycle, or when sudden stoppage of oscillation occurs, short start-up time for oscillation start-up, quick start-up, and low power consumption during steady-state oscillation after oscillation start-up It is another object of the present invention to provide a low-cost oscillating device which can cope with an oscillation / stop cycle, has a simple structure, has a small number of parts, minimizes overhead power consumption, and has a low cost.

[0011]

According to the present invention, there is provided an oscillation apparatus comprising: an oscillation circuit for an oscillation vibrator;
An oscillation detection circuit that detects an operation of the oscillation circuit; a constant voltage circuit that supplies at least a high-low voltage to the oscillation circuit; and a constant voltage circuit that oscillates based on an output of the oscillation detection circuit. The low voltage output by the voltage circuit is supplied to the oscillation circuit, and while the oscillation circuit is stopped oscillating,
Switching means for supplying the high voltage output from the constant voltage circuit to the oscillation circuit.

Alternatively, an oscillation device according to the present invention comprises an oscillation circuit for an oscillation oscillator, an oscillation detection circuit for detecting the operation of the oscillation circuit, and a constant current supply circuit for supplying at least a large and small current to the oscillation circuit. A current circuit that supplies the small current output by the constant current circuit to the oscillation circuit while the oscillation circuit is oscillating based on an output of the oscillation detection circuit; Switching means for supplying the large current output from the circuit to the oscillation circuit.

According to the oscillating device according to the present invention having the above-described configuration, low power consumption and oscillation start-up time are reduced by the switching means that operates based on the output of the oscillation detecting circuit, and the oscillation detecting circuit constantly operates in the oscillation state. Is monitored, and a quick and smooth operation at the time of oscillation / stop cycle or oscillation restart is enabled.

Alternatively, in the case where the semiconductor integrated device according to the present invention is configured to include the oscillation device according to claim 1 or 2, the efficiency of the integrated circuit is reduced by reducing the size of peripheral circuits and saving power. The device is realized.

[0015]

Embodiments of the present invention will be described below. FIG. 1 is a block diagram showing an oscillator according to an embodiment of the present invention. As shown in the figure, an oscillation device OS1 according to the present invention includes an oscillation oscillator 1, an oscillation circuit 2,
It comprises an oscillation detection circuit 3, an analog switch 4, an analog switch 7, an inverter 5, and a constant voltage circuit 6 for outputting high-low binary voltages V1 and V2. The power supply circuit further includes a power supply circuit (not shown). The power supply circuit supplies a drive current to the oscillation detection circuit 3, analog switches 4 and 7, and circuit elements constituting the inverter 5.

The oscillation circuit 2 is connected to an oscillation oscillator 1 such as a quartz oscillator. The output 2a from the oscillation circuit 2 is supplied to the outside as an output signal of the oscillation device OS1, and the output 2a from the oscillation circuit 2 is also input to the oscillation detection circuit 3 at the same time. And monitors whether the oscillation circuit 2 is in an oscillating state or in an oscillating stopped state based on the state of the oscillation circuit 2, and outputs the result as a signal 3a. The signal 3a is a logical output. For example, when the oscillation circuit 2 is in the oscillation state, the signal 3a outputs an L level, and when the oscillation circuit 2 is in the oscillation stop state, the H level is output.

Analog switches 4 and 7, inverter 5
Constitute switching means. The signal 3a from the oscillation detection circuit 3 is supplied to the analog switch 4 as a control signal and also to the inverter 5, and the signal 5a, the polarity of which is inverted by the inverter 5, is
It is supplied to the analog switch 7 as a control signal.
The analog switch 4 turns on and off the voltage V1 supplied from the constant voltage circuit 6 to the oscillation circuit 2 based on the control signal 3a. On the other hand, the analog switch 7 controls the voltage V2 supplied from the constant voltage circuit 6 to the oscillation circuit 2 based on the control signal 5a.
On and off.

The constant voltage circuit 6 supplies a high voltage V1 and a low voltage V2 to the oscillation circuit 2 via the switching means. As a result, based on the output 3a of the oscillation detection circuit 3, the low voltage V2 is supplied to the oscillation circuit 2 via the analog switch 7 while the oscillation circuit 2 is oscillating, and to the oscillation circuit 2 while the oscillation circuit 2 is stopped. The high voltage V1 is supplied via the analog switch 4. As described above, in this embodiment, a method of driving the oscillation circuit by the voltage source is employed.

The oscillation device OS1 operates as follows. First, when the oscillation circuit 2 is not triggered and the oscillation is stopped, the oscillation detection circuit 3 detects this state,
Since the logic signal 3a of the level is output, the analog switch 4 is in the ON state, and the high voltage V1 is supplied to the oscillation circuit 2 via the analog switch 4. On the other hand, the analog switch 7 is off.

Here, when a trigger signal is given to the oscillation circuit 2 from an external system and triggered, the oscillation circuit 2 is started up in an extremely short time because the high voltage V1 is supplied to the oscillation circuit 2. That is, it can be started with the shortest start lead time.

When the start-up is completed and a steady oscillation output is obtained, the oscillation detection circuit 3 detects this state and outputs an L level logic signal 3a. The analog switch 4 is switched from on to off by the L-level logic signal 3a, and the supply of the high voltage V1 to the oscillation circuit 2 is cut off. On the other hand, the analog switch 7 switches from off to on, and the low voltage V2 is supplied to the oscillation circuit 2.

As described above, while the oscillation oscillator is driven and the oscillation circuit is oscillating and outputting, a relatively low voltage is supplied to realize low power consumption. Further, when the oscillation oscillator is not driven and the oscillation circuit is stopped, a relatively high voltage is supplied to the oscillation circuit to shorten the startup time of the oscillation oscillator when triggered.

As a result, the apparatus of the present invention is different from the conventional apparatus in that the oscillation / stop cycle is repeated, or the oscillation of the oscillation / stop cycle is repeated. Cycles can be accommodated, the oscillation start time is short, quick start-up is possible, and power consumption can be reduced during steady oscillation after oscillation start. Moreover, since the configuration is simple, the number of parts is small, and furthermore, the overhead power consumption of the oscillation detection circuit and the like is small, so that low cost can be realized.

In the above description, the start timing of the oscillation circuit is described as being based on an external trigger. However, the present invention is not limited to this, and an internal trigger configuration or a configuration in which the trigger is omitted may be employed. Further, by configuring the semiconductor integrated device including the above-described oscillation device, it is possible to provide an efficient semiconductor integrated device in which the size of peripheral circuits is reduced and power consumption is reduced.

FIG. 2 is a block diagram showing another embodiment of the oscillation device according to the present invention. The same parts as those in the above embodiment are denoted by the same reference numerals. As shown in the figure, the oscillation device OS2 according to the present embodiment includes an oscillation oscillator 1, an oscillation circuit 2, an oscillation detection circuit 3, an analog switch 4, an analog switch 7, an inverter 5, a large and small binary current i1, It comprises a constant current circuit 16 that outputs i2. The power supply circuit further includes a power supply circuit (not shown). The power supply circuit supplies a drive current to the oscillation detection circuit 3, analog switches 4 and 7, and circuit elements constituting the inverter 5.

Analog switches 4 and 7, inverter 5
Constitute switching means. The analog switch 4 turns on and off the current i1 supplied from the constant current circuit 16 to the oscillation circuit 2 based on the control signal 3a. On the other hand, the analog switch 7 turns on and off the current i2 supplied from the constant current circuit 16 to the oscillation circuit 2 based on the control signal 5a.

The constant current circuit 16 supplies a large current i1 and a small current i to the oscillation circuit 2 via the switching means.
2 are supplied. As a result, the output 3 of the oscillation detection circuit 3
a, a small current i2 is supplied to the oscillation circuit 2 via the analog switch 7 while the oscillation circuit 2 is oscillating, and a large current i1 is supplied to the oscillation circuit 2 via the analog switch 4 while the oscillation circuit 2 is stopped. Supplied. As mentioned above,
In this embodiment, a method of driving an oscillation circuit by a current source is employed. The operation and effects are the same as in the above embodiment.

[0028]

As described in detail above, claim 1 of the present invention
The oscillation device according to the above is configured to include an oscillation detection circuit that detects the operation of the oscillation circuit, switching means that operates based on the output of the oscillation detection circuit, and a constant voltage circuit that supplies at least high-low binary voltage. The oscillation / stop cycle can be shortened by shortening the startup time by supplying a high voltage when oscillating, and maintaining low power consumption by supplying a low voltage while oscillating. Alternatively, a quick and smooth starting operation at the time of restarting the oscillation becomes possible.

An oscillation device according to a second aspect of the present invention provides an oscillation detection circuit for detecting the operation of the oscillation circuit, a switching means that operates based on the output of the oscillation detection circuit, and supplies at least a current of at least two values. Since it is configured with a constant current circuit, the start-up time is shortened by supplying a large current when oscillating, and the oscillation is maintained with low power consumption by supplying a small current when oscillating. By monitoring, there is an effect that a quick and smooth starting operation at the time of the oscillation / stop cycle or the restart of the oscillation becomes possible.

A semiconductor integrated device according to a third aspect of the present invention is provided with the oscillation device according to the first or second aspect. Therefore, the size and power consumption of the peripheral circuit are reduced by the integrated circuit. And an efficient device can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of an oscillation device according to the present invention.

FIG. 2 is a block diagram of another embodiment of the oscillation device according to the present invention.

FIG. 3 is a block diagram of a conventional oscillation device.

[Explanation of symbols]

 OS1 oscillator 1 Oscillator 2 Oscillator 2a Oscillation output 3 Oscillation detection circuit 3a Logic output signal 4 Analog switch 5 Inverter 6 Constant voltage circuit 7 Analog switch V1 High voltage V2 Low voltage

Claims (3)

[Claims] An oscillation circuit for an oscillation oscillator; an oscillation detection circuit for detecting an operation of the oscillation circuit; a constant voltage circuit for supplying at least a high-low voltage to the oscillation circuit; While the oscillation circuit is oscillating based on the output, the low voltage output by the constant voltage circuit is supplied to the oscillation circuit, and while the oscillation circuit is not oscillating, the high voltage output by the constant voltage circuit is supplied. An oscillation device comprising: switching means for supplying the oscillation circuit. 2. An oscillation circuit for an oscillation vibrator; an oscillation detection circuit for detecting an operation of the oscillation circuit; a constant current circuit for supplying at least a large or small current to the oscillation circuit; While the oscillation circuit is oscillating based on the output, the small current output by the constant current circuit is supplied to the oscillation circuit, and while the oscillation circuit is stopped oscillating, the large current output by the constant current circuit is supplied. An oscillation device comprising: switching means for supplying the oscillation circuit. 3. A semiconductor integrated device comprising the oscillation device according to claim 1.