JP2527998Y2 - Portable electronic devices - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable electronic device having a built-in IC, and more particularly to a portable electronic device with reduced power consumption.

[0002]

2. Description of the Related Art A conventional battery-powered device in consideration of expandability generally includes a battery 31 as a main power source, as shown in FIG.
A power supply circuit 32 that outputs a constant voltage using the battery 31 as a power source and supplies power to an electronic circuit 33 and a peripheral device interface 35, an electronic circuit 33 that actually performs system processing of the device, and an interface 35 with the peripheral device It is composed of The peripheral device interface 35 has a power supply line 351 for supplying power to the peripheral device, and a bus 352 for exchanging data between the electronic circuit 43 of the peripheral device 40 and the electronic circuit 33 of the battery-driven device 30. The peripheral device 40 that can be connected to the battery-driven device 30 is a peripheral device 4
It is composed of an electronic circuit 43 for performing the processing of 0. Then, by connecting the battery-driven device 30 and the peripheral device 40 through the peripheral device interface 35, the electronic circuit 43 is supplied with power from the power supply line 351 of the peripheral device interface 35, and the electronic circuit 43 of the battery-driven device 30 is connected via the bus 352. Data is exchanged with the circuit 33.

In particular, a power supply circuit 32 is necessary for making the output voltage of the battery 31, which varies greatly depending on the environment, constant and supplying it to an electronic circuit. Therefore, in order to keep the battery voltage at a constant voltage, the power supply circuit 32 steps up or down to supply power to the electronic circuit 33 of the battery-driven device 30.

In order to reduce the power consumption of the electronic circuit 33, a low power consumption CMOS IC is often used. Since the power consumption is proportional to the power supply voltage as a characteristic of the CMOS IC, The power supply voltage is set to a voltage (about 3 V) lower than the power supply voltage (5 V) normally used for TTL or the like. However, the ICs are designed specifically for low-voltage operation or use ordinary power supply voltages (5
The low voltage operation is specially guaranteed by selecting from those designed in V).

[0005] Further, since the battery-driven device 30 is important in portability, it is required to be small and light. Similarly, since the peripheral device 40 is also required to be reduced in size and weight, the peripheral device 40 itself does not have a power supply and a power supply circuit, and often uses the power supplied from the power supply circuit 32 as its own power supply.

[0006]

SUMMARY OF THE INVENTION When an attempt is made to use an IC that can operate only at a normal power supply voltage (5 V) in a conventional portable electronic device, the power supply voltage of the battery-driven device is raised to the normal power supply voltage. There must be.

In particular, when a peripheral device to which a battery-driven device supplies power uses an IC that can operate only at a normal power supply voltage, the power supply voltage of the battery-driven device is also reduced to the normal power supply voltage (5 V). Must be set. However, even when this peripheral device is not used, the power supply voltage of the battery-driven device must be set to be high, so that there is a problem that the power consumption of the battery-driven device is increased and the battery life is shortened. Was.

For example, when it is desired to use an IC such as an electronic organizer to which a special function can be added by an IC card and which can operate only at a normal power supply voltage (5 V) in the IC card, a power supply voltage of the electronic organizer is required. Must be set high. However, in such a case, even when the IC card is not used, there is a problem that the power supply voltage on the electronic notebook side remains high, the power consumption is increased, and the battery life is shortened.

Therefore, an object of the present invention is to provide a portable electronic device capable of extending the battery life when a peripheral device requiring a normal power supply voltage (5 V) is not connected to the battery-driven device. It is in.

[0010]

SUMMARY OF THE INVENTION Accordingly, in order to achieve the above object, the portable electronic device of the present invention has a battery, a first electronic circuit for performing system processing, and a peripheral device interface for exchanging various signals. A battery-powered device having a power supply circuit that outputs a constant voltage using the battery as a power source and supplies power to the electronic circuit and peripheral device interfaces, a second electronic circuit that performs system processing, and controls the power supply circuit And a peripheral device having a control circuit therefor.

Further, the peripheral device interface includes:
A power supply line for supplying power to peripheral devices, a bus for exchanging data between the second electronic circuit and the first electronic circuit, and a signal line for transmitting a control signal for an output voltage of the power supply circuit It is characterized by the following.

[0012]

A peripheral device that shares a power supply with a battery-driven electronic device can be connected. The interface has a control line for controlling the power supply voltage, and a power supply circuit for changing the power supply voltage by the control line. In the present invention, for example, a power supply circuit in which a power supply voltage control line is set to a low power supply voltage (about 3 V) when open and a normal power supply voltage (5 V) when grounded is realized in a battery-driven device. By grounding a control line for controlling the power supply voltage of a peripheral device requiring a normal power supply voltage, the power supply of the battery-driven device is not connected to the normal power supply voltage (5 V) when the peripheral device is connected. In this case, the power supply voltage is set to a low power supply voltage.

Therefore, the power supply voltage of the battery-driven device can be set to an optimum value depending on whether or not a peripheral device requiring a normal power supply voltage (5 V) is connected. Since the power supply voltage of the mold device can be reduced, power consumption can be reduced. Then, the battery life is prolonged by reducing the power consumption.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing an embodiment of a portable electronic device according to the present invention. In FIG. 1, a battery-driven device 10 includes a battery 11, a power supply circuit 12 that outputs a constant voltage using the battery 11 as a power source, and supplies power to a first electronic circuit 13 and a peripheral device interface 15. It comprises a first electronic circuit 13 for performing system processing of the device and a peripheral device interface 15. The peripheral device interface 15 includes a power supply line 151 for supplying power to the peripheral device 20, and a bus 152 for exchanging data between the second electronic circuit 23 of the peripheral device 20 and the first electronic circuit 13 of the battery-driven device 10. And a signal line 153 for transmitting a control signal of an output voltage of the power supply circuit 12. Then, the power supply circuit 12 outputs a power supply voltage according to the state of the control line 153 of the output voltage of the peripheral device interface 15.

The peripheral device 20 includes a second electronic circuit 23 for performing processing of the peripheral device 20 and a control circuit 24 for controlling the power supply circuit 12. And the battery-driven device 1
0 and the peripheral device 20 through the peripheral device interface, so that the second electronic circuit 23 and the control circuit 2 are connected.
4 is supplied with power from a power supply line 151 of the peripheral device interface 15, the second electronic circuit 23 exchanges data with the first electronic circuit 13 of the battery-driven device 10 via a bus 152, and the signal line 153 is a battery. A signal from the control circuit 24 is transmitted to the power supply circuit 12 of the drive type device 10.

The battery-driven device 10 constructed as described above
The battery-driven device 1 depends on whether or not the peripheral device 20 is connected.
The power supply voltage of the power supply circuit 12 of 0 can be changed. Therefore, when the peripheral device 20 requiring the normal power supply voltage is connected, the output voltage of the power supply circuit 12 is set to the high voltage required by the peripheral device 20, and when the peripheral device 20 is not connected, the power supply circuit 12 is set. Is set to a power supply voltage that is low enough for the first electronic circuit 13 in the battery-driven device 10 to operate.

That is, when the peripheral device 20 is not connected, the power supply voltage of the battery-driven device 10 can be reduced, so that power consumption can be reduced. Then, the battery life is prolonged by reducing the power consumption.

[0018]

[Effects of the Invention] As described above, in the present invention, it is possible to connect a peripheral device that shares a power supply with a battery-driven electronic device,
It has a control line for controlling the power supply voltage in the interface,
A power supply circuit for changing the power supply voltage by the control line is provided, and the voltage of the power supply of the battery-driven device can be set to an optimum value depending on whether or not a peripheral device requiring a normal power supply voltage (5 V) is connected. When the peripheral device is not connected, the power supply voltage of the battery-operated device can be reduced, so that the power consumption can be reduced, and the reduction of the power consumption results in a longer battery life.

[Brief description of the drawings]

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

FIG. 2 is a block diagram showing a conventional portable electronic device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Battery-driven apparatus 11 Battery 12 Power supply circuit 13 1st electronic circuit 15 Peripheral device interface 151 Power supply line 152 Bus 153 Signal line 20 Peripheral device 23 Second electronic circuit 24 Control circuit

Claims (2)

(57) [Scope of request for utility model registration] 1. A battery, a peripheral device interface for exchanging various signals with a first electronic circuit for performing system processing, and a constant voltage output by using the battery as a power source to supply power to the electronic circuit and the peripheral device interface. A battery-driven device having a power supply circuit for supplying the power, a second electronic circuit for performing system processing, and a peripheral device having a control circuit for controlling the power supply circuit. Portable electronic devices. 2. The power supply line for supplying power to a peripheral device, a second electronic circuit and a first electronic circuit.
2. The portable electronic device according to claim 1, further comprising a bus for exchanging data of the electronic circuit, and a signal line for transmitting a control signal of an output voltage of the power supply circuit.