JP4221665B2 - Mobile terminal device - Google Patents

Description

  The present invention relates to battery power supply for a mobile phone, and more particularly to a mobile terminal device having a power supply switching control function when a second battery is mounted.

  In order to reduce the size and thickness of mobile phone devices, the size of the battery used is one of the important factors. In recent years, as a technology for making such a battery very thin, Development and commercialization of a battery in which a negative electrode is laminated and compressed thinly with a laminate film to form a “laminated laminate shape” has been progressing.

  If such a battery is used, it becomes possible to incorporate the battery in a PCMCIA card type PHS device or the like currently used for data communication. Currently, such a PHS device is inserted into the PCMCIA slot of a notebook PC, and it is operated to receive a power supply from the notebook PC to achieve a desired function. It becomes possible to see not only data communication but also development for voice communication. Further, it is possible to analogize and realize the mounting of the battery not only in the PHS device but also in mobile terminal devices of various mobile phone systems (PDC, GSM, WCDMA). However, as a problem when using such a battery, there is a drawback that the battery capacity is small.

On the other hand, there has been proposed a conventional communication terminal device that is reduced in size and weight, or that has a battery circuit configured to use an internal battery and an external battery and use them appropriately as required so as to extend the operating time ( Patent Document 1).
The battery circuit includes an external battery and an internal battery that are detachably attached to the communication terminal device housing, and a first drive voltage supplied from the external battery when the external battery is attached. Is supplied to the circuit of the communication terminal device and driven, and when the external battery is not attached, the second drive voltage supplied from the internal battery is supplied to the circuit and driven. The second drive voltage is used by switching. Further, in this portable terminal device, when the external battery is mounted and used, the external battery 3 operates preferentially according to the comparison result between the first drive voltage and the reference voltage, and the external battery Even if the battery is overdischarged, it can be operated by using both batteries continuously by switching to the internal battery, and the operation time can be greatly extended compared with the conventional portable terminal device ( Patent Document 1 (3) Battery switching process).

JP 2000-101696 A

  As described above, in a communication terminal device mounted with a small internal battery, although the capacity is small due to the miniaturization and weight reduction of the mobile terminal device, a second battery (externally attached) is required to increase the operating time when carrying the device. In this case, the built-in battery is configured to be charged by connecting an ordinary AC / DC adapter externally, and the external battery can be charged by other means. It becomes the structure which charges using a charger.

  However, in this method, the internal battery and the external battery are charged by different methods, and in particular, the power supply system is not easy to use due to the special handling of the external battery. There is a problem in that it does not get.

  In particular, the size of the PCMCIA (TYPE 2) PHS device, etc., which is widely used, is defined as 85.6 × 54.0 × 5.0 mm. To insert a battery into this shape, the height of the battery is When the limit is estimated to be about 1.5 mm and the battery area is assumed to be 50 × 50 mm, the capacity value of the battery is estimated to be about 200 mAh. Since this capacity value is very small compared with the battery capacity value of 600 to 700 mAh used in the current mobile phone models, the battery life is extremely shortened. Although it is conceivable to use the configuration, there is a similar problem in the power supply system in this case as well.

An object of the present invention is to solve the above-described problems, and to provide a portable terminal device capable of extending the battery life by externally attaching a second battery (external battery).
Another object of the present invention is to provide a portable terminal device having an easy-to-use power supply switching system between an internal battery and an external battery.
Another object of the present invention is to provide a portable terminal device having a power supply switching system capable of charging an external battery by a built-in battery charging circuit.
Another object of the present invention is to provide a PCMCIA card type portable terminal device to which an external battery can be externally attached.

The portable terminal device of the present invention supplies power to a regulator (for example, 2 in FIG. 2) from a charging circuit (for example, 1 in FIG. 2) connectable with a charging adapter (for example, B in FIG. 2) and the charging circuit. In a portable terminal device having a power line, a built-in battery (for example, 4 in FIG. 2), a first switch (for example, 31 in FIG. 2) connected between the output terminal of the built-in battery and the power line, and an external A battery connection terminal (for example, 7 in FIG. 2) connectable with an output terminal of a battery (for example, 5 in FIG. 2), and a second switch (for example, in FIG. 2) connected between the battery connection terminal and the power line. 32) and when the voltage of the battery connection terminal is equal to or higher than a predetermined reference voltage (for example, Vref in FIG. 2), only the second switch (for example, 32 in FIG. 2) is controlled to be in an ON state, and less than the reference voltage. If the and a control circuit of the first and second switches for controlling the first switch (e.g. 31 in FIG. 2) only in the on-state (e.g., 35, 36, and 37 in FIG. 2), wherein the internal battery or external By connecting the charging adapter to the charging circuit when power is supplied from the battery to the power supply line, power is supplied from the charging circuit to the regulator, and the built-in battery is connected via the first or second switch, respectively. Alternatively, an external battery can be selectively charged .

  Also, third and fourth switches (for example, 61 and 62 in FIG. 2) connected between the charging circuit and the power supply line and between the charging circuit and the battery connection terminal, respectively, And an operation unit (63 in FIG. 2) for switching the on / off state of the fourth switch in opposite directions.

A portable terminal device according to the present invention includes a charging circuit connectable to a charging adapter, and a power supply line that supplies power from the charging circuit to a regulator, and is connected in series between the charging circuit and the power supply line. Built-in output terminal connected to the connection point of the third switch (for example, 61 in FIG. 3) and the first switch connected to, and the connection point of the third switch and the first switch (for example, 38 in FIG. 3) A battery, a battery connection terminal connectable to the output terminal of the external battery, a second switch (for example, 32 in FIG. 3) connected between the battery connection terminal and the power supply line, the charging circuit, and the battery A fourth switch (for example, 62 in FIG. 3) connected to the connection terminal, an operation unit for switching the on / off states of the third and fourth switches in opposite directions, and a front When the voltage of the battery connection terminal is equal to or higher than a predetermined reference voltage, only the second switch is controlled to be on, and when the voltage is less than the reference voltage, only the first switch is controlled to be on. A control circuit of the switch (for example, 35, 36, 34 in FIG. 3), and by connecting the charging adapter to the charging circuit when power is supplied from the built-in battery or an external battery to a power supply line, Power is supplied to the regulator, and the built-in battery or the external battery can be selectively charged via the third or fourth switch, respectively .

  Further, the reference voltage is a low voltage alarm voltage value (for example, LVA in FIG. 3: 3.6V) that is an input voltage of the regulator when outputting the lowest power supply voltage that can ensure the operation characteristics of the circuit that operates with the output of the regulator. ).

  The portable terminal device includes a PCMCIA interface unit that can be inserted into a PCACIA card slot of a personal computer, and the charging circuit can be connected to a power source unit in the PCACIA card slot instead of a charging adapter. (For example, FIG. 8).

(Function)
In order to extend the battery life of the mobile terminal device, the present invention extends the battery life by connecting an external battery such as a lithium ion battery from the outside in parallel with the internal battery such as a lithium ion battery that is already mounted. It has a function to control the switching of two batteries that can be performed, avoids charging / discharging between the two batteries, and connects / disconnects external batteries to / from AC / DC adapters. Accordingly, it has a function of automatically switching power supply from the battery, a switching function of suitably charging each battery, and further has the following functions.

  1. When the voltage value of the low voltage alarm (LVA) voltage set inside the mobile terminal device is used as a reference voltage and the voltage value of the external battery is larger than this, the external battery is given priority over the built-in battery to power the circuit. Supply. In other words, the priority relationship with the built-in battery when the external battery is installed is that the power supply to the circuit is given priority when the voltage value of the external battery is higher than the low voltage alarm voltage value of the battery used in the mobile terminal device. Functions to perform, 2. 2. A function to supply power from the built-in battery to the circuit when the voltage value of the external battery falls below the low voltage alarm voltage value. 3. A function of charging each battery in parallel with power supply when the AC / DC adapter is connected, regardless of whether an external battery is attached or not. It has a function of charging the discharged external battery separately by the AC / DC adapter.

  According to the present invention, each of the internal battery 4 and the external battery 5 that is detachable from the outside can be used effectively, the battery life can be improved, and power can be supplied from the charging circuit to the regulator. It is possible to charge any of the batteries.

  Further, the external battery can be charged by the same charging circuit as that of the built-in battery by providing a switch between the charging circuit and the power supply line and the battery connection terminal of the external battery.

  Furthermore, it is possible to prevent malfunction of the circuit of the portable terminal device by switching from the external battery that supplies power to the built-in battery when the voltage of the external battery reaches the low voltage alarm voltage value.

  In addition, a built-in battery and an external battery can be appropriately charged from a single AC / DC adapter, a charger such as a notebook PC, etc., and an easy-to-use power supply system can be realized, and also to a PCMCIA (TYPE 2) PHS device, etc. It is suitable for application.

Next, an example of a mobile phone as an embodiment of the mobile terminal device of the present invention will be described in detail below with reference to the drawings.
(Description of configuration)
FIG. 1 is a diagram showing a configuration of a mobile phone as an embodiment of the present invention. The mobile phone main body constitutes a power supply switching system according to the present invention in which power is supplied to each circuit block in addition to an input / output unit such as a radio unit RF, a baseband processing unit BB having a memory, an LCD display, and a key input key. A power control unit A and a built-in battery (V1) are provided. The power supply control unit A has an external battery (V2) as a second battery detachable, and further includes an AC / DC adapter B that supplies power to the mobile phone as an external power supply and charges the battery.

  FIG. 2 is a diagram showing a power supply component of the cellular phone according to the present embodiment. The configuration of the power control unit A in the mobile phone main body can be connected to a charging AC / DC adapter B independent of the main body, and is used to supply power and charge the battery when connected to the AC / DC adapter B. Charging IC 1, each regulator 2 to which a battery voltage is applied and outputting a stabilization voltage, an internal battery 4 mounted inside the mobile phone, an external battery 5 as an external second battery, and the voltages of these batteries A battery switching circuit 3 to be applied to each regulator 2, a charging switch 6 between the charging IC 1 and the battery switching circuit 3, and a battery connection terminal 7 to which the external battery 5 is connected.

  The battery switching circuit 3 does not cause a charge / discharge operation between the external battery 5 and the built-in battery 4 when the external battery 5 is connected, and the amount of charge of the external battery 5 remains necessary for driving each regulator 2. The switching circuit is used in preference to the built-in battery 4 as long as it has a certain amount, and realizes automatic control so as to switch to the built-in battery 4 with a remaining amount equal to or less than a predetermined value.

  A p-channel insulated field effect transistor (P-MOS transistor) 31 connected between the built-in battery 4 and the power supply line, a P-MOS transistor connected between the battery connection terminal 7 connected to the external battery 5 and the power supply line 32, a differential type comparator (comparator) in which a pull-down resistor 36 to ground is connected to the internal wiring of the battery connection terminal 7, a non-inverting input terminal is connected to the internal wiring, and a reference voltage Vref is connected to the inverting input terminal. 35), the output of the AND circuit 37 whose output is connected to the gate electrode of the P-MOS transistor 31 and the output of the two inverter circuits 33 having the internal wirings as inputs are compared with one input terminal of the AND circuit 37. The output of the comparator 35 is connected to the other input terminal of the AND circuit 37, and the output of the comparator 35 is further connected to the inverter circuit. 4 through having the configuration that is connected to the gate electrode of the P-MOS transistor 32. Note that the output of the comparator 35 can be directly connected to the gate electrode of the P-MOS transistor 31.

  The charging switch 6 includes a switch 61 connected in series between the charging IC 1 and the power supply line of the battery switching circuit 3, and a switch 62 between the charging IC 1 and the battery connection terminal 7 of the external battery 5. The switch 61, 62 is controlled to be switched so that the on / off operation is reversed by the operation of the operation unit 63 such as a button. Here, the switches 61 and 62 can be composed of high-power P-MOS transistors.

(Description of operation)
Next, the operation of the embodiment of the present invention will be described in detail with reference to the drawings.
First, the operation of the battery switching circuit 3 that supplies power from the internal battery 4 and the external battery 5 to each regulator will be described.

  If the built-in battery 4 is in a charged state and the external battery 5 is not connected to the battery connection terminal 7, the voltage level of the battery connection terminal 7 is at the low level by the pull-down resistor 36, and the comparator 35 is at the low level. A signal (Low level) is output. Therefore, the inverter circuit 34 outputs a High level signal (High level), the P-MOS transistor 32 is in an off (cut off) state, and power is supplied from the built-in battery 4 to each regulator 2. The mobile phone can be operated for a relatively short time due to the built-in battery 4 having a small capacity, and the mobile phone function is reset.

  On the other hand, when the external battery 5 in a charged state is connected to the battery connection terminal 7 and used, the voltage level of the battery connection terminal 7 becomes a high level, so the comparator 35 outputs a high level. As a result, the inverter circuit 34 outputs a low level, the P-MOS transistor 32 is turned on (conductive), and power is supplied from the external battery 5 to each regulator 2. At this time, the high-level output of the comparator 35 and the high-level output of the two-stage inverter circuit 33 cause the P-MOS transistor 31 to be turned off by the high-level output of the AND circuit 37, and the charge / discharge operation between the batteries is performed. Can be avoided.

  Next, when the amount of charge of the external battery 5 gradually decreases and the voltage at the battery connection terminal 7 decreases and falls below the reference voltage Vref, the comparator 35 switches to the low level, the inverter circuit 34 outputs the high level, P The MOS transistor 32 is turned off. At this time, the inputs of the AND circuit 37 are all at the low level, the P-MOS transistor 31 is turned on, and power is supplied from the built-in battery 4 to each regulator 2. Also in this case, the charge / discharge operation between the batteries can be avoided. Use of the external battery 5 greatly extends the usable time of the mobile phone.

  As described above, according to the battery switching circuit 3 of the present embodiment, when the external battery 5 is connected, no charging / discharging operation occurs between the external battery 5 and the built-in battery 4, and the charge amount of the external battery 5 Is used in preference to the built-in battery 4 as long as it has a remaining amount necessary for driving each regulator 2, and automatically switches to the built-in battery 4 with a remaining amount equal to or less than a predetermined value. Further, the external battery 5 can be automatically supplied from the built-in battery 4 to each regulator by appropriately removing the external battery 5 in a state having a sufficient remaining amount in order to reduce the weight of the mobile phone.

  Next, the operation of the embodiment of the present invention in which the charging switch 6 is added to the charging operation of the batteries 4 and 5 will be described. The charging switch 6 is a switch 61 between the power supply line of the charging IC 1 and the battery switching circuit 3, a switch 62 between the power supply line of the charging IC 1 and the battery connection terminal 7 of the external battery 5, and both switches 61, 62 are turned on and off in opposite directions. And an operation unit 63 that performs switching.

  The charging switch 6 is set in the on state and the switch 62 in the off state in the normal use state. In this state, for example, the external battery 5 is connected and power is supplied from the external battery 5 to each regulator 2 to operate (the built-in battery 4 is disconnected by the P-MOS transistor 31).

  Here, when the AC / DC adapter B is connected, power is supplied from the charging IC 1 to each regulator 2. In this case, the capacity of the charging IC 1 can be set so that the charging current flows from the charging IC 1 to the external battery 5 via the P-MOS transistor 32. That is, the charging operation can be performed by the charging IC 1 unless the external battery 5 is in an overdischarged state.

  Further, when the AC / DC adapter B is connected when the external battery 5 is not connected, the P-MOS transistor 31 is in the ON state by the above-described operation, so that power is supplied from the charging IC 1 to each regulator 2. In addition, a charging current flows from the charging IC 1 to the built-in battery 4 so that a charging operation is possible.

  It is obvious that the above operation can be realized by any combination of connection or removal of the external battery 5 and connection and removal of the AC / DC adapter B.

  Next, when the AC / DC adapter B is connected and the external battery 5 is connected in an overdischarged state, the charging operation is performed by switching the on / off state of the charging switch 6 with the operation unit 63. Is possible. That is, in this case, since the switch 61 is in the off state, each regulator 2 is supplied with power from the built-in battery 4, while the switch 62 is in the on state, so that the external battery 5 is charged from the charging IC 1 via the switch 62. The Here, when the terminal voltage of the external battery 5 becomes larger than the reference voltage Vref of the comparator 35, the ON / OFF relationship of the P-MOS transistors 31 and 32 is reversed, and the P-MOS transistor 32 switched from the charging IC 1 to the ON state is inverted. Power is supplied to each regulator.

  With the above operations and functions of the present embodiment, it is possible not only to operate the mobile phone only with the built-in battery 4 but also to operate by preferential use of the external battery with the external battery 5 attached. When the battery 5 is overdischarged, the external battery 5 can be charged, or the overdischarged external battery 5 can be connected to the mobile phone and charged. It is possible to connect or disconnect the AC / DC adapter B as appropriate when the mobile phone is in use.

(Other embodiments)
A more specific configuration example of a mobile phone according to another embodiment of the present invention will be described below.
FIG. 3 is a diagram showing the configuration of the present embodiment. The AC / DC adapter B has an AC input of 250V to 100V and a DC output of 6.5V to 4.5V. The built-in battery 4 and the external battery 5 are rechargeable ion batteries having a battery voltage range of 4.2 V to 3.0 V (the battery maximum voltage is controlled to 4.2 V during charging), and the reference voltage of the comparator 35 is a low voltage. The voltage value (low voltage alarm voltage) of the alarm (LVA: Low Voltage Alarm) is used. The low voltage alarm voltage value is set by the input voltage value of the regulator that can ensure the normal operating characteristics of each circuit operated by the output of the regulator of the cellular phone, and about 3.6V to 3.3V is adopted. In this embodiment, it is set to 3.6V. In this embodiment, the switch configuration of the battery switching circuit 3 is further provided with a P-MOS transistor 38 connected in series to a switch 61 connected in series to the output terminal of the charging IC 1 to connect the charging IC 1 and the power supply line, The gate electrode of the P-MOS transistor 38 is connected to the output of the comparator 35.

  FIG. 4 is a diagram showing the configuration of power supply and charging by the charging IC 1, and FIG. 5 is a diagram showing the configuration of each regulator. The regulator supplies the power to each circuit by making the voltage of the battery constant through the regulator so as not to be affected by voltage fluctuations due to the discharge characteristics of the battery. Each regulator includes a regulator 1 that outputs 3.3 V to the radio (RF) unit, regulators 2 and 3 that output 1.8 V to the baseband processing unit and the memory unit, and 3.3 V to a microphone / speaker, etc. And a low voltage detection circuit that outputs a low voltage alarm voltage value of 3.6 V to 3.3 V from the input voltage of the regulator and outputs a system reset signal when the voltage is less than 3.3 V.

  FIG. 6 is a diagram showing the discharge characteristics of the lithium ion battery, and FIG. 7 is a diagram showing the discharge of the internal battery 4 and the external battery 5 and the transition of the battery operation. The battery maximum voltage is controlled to 4.2 V at the time of charging, and this voltage value becomes the maximum value so that power is supplied to the circuit, and the battery voltage has a characteristic of discharging current to about 3.0 V. The battery output voltage gradually decreases from a maximum of 4.2 V according to the discharge capacity (mAh), and becomes overdischarged by discharge of about 200 mAh. As shown in FIG. 7, when the external battery 5 is mounted, the discharge operation starts from the external battery 5 (t1), and when the output voltage becomes less than LVA (3.6V) of the comparator, the output of the comparator 35 becomes Low. As a result, the P-MOS transistor 38 is turned on (ON; conductive), the P-MOS transistor 32 is turned off (OFF; cut off), the power supply to the circuit is switched to the internal battery 4, and the built-in battery starts discharging. (T2). The built-in battery 4 gradually decreases according to the discharge capacity (mAh) from 4.2 V at the start of discharge (t2), and when the output voltage becomes less than 3.6 V, a low voltage alarm is generated to prevent circuit malfunction due to the low voltage of the battery. For the purpose of 3.3V, the mobile phone function is forcibly reset.

  With the above control, the battery life of the mobile phone is configured to depend on the capacity of the battery 4 + battery 5, and the two batteries 4, 5 can be used efficiently. In the present embodiment, it is possible to supply power to the circuit from the AC / DC adapter B and charge the built-in battery 4. Although charging to the external battery 5 cannot be performed from the P-MOS transistor 32, it is apparent from the above description that the charging operation can be performed by turning on the switch 62 by operating the operation unit 63.

(Other embodiments)
FIG. 8 is a diagram showing an embodiment applied to a PMC device of PCMCIA (TYPE 2). In this embodiment, a PCMCIA size (TYPE2) mobile phone is equipped with a PCMCIA interface that can be inserted into a PCMCIA slot provided in a notebook personal computer (notebook PC). By inserting the mobile phone into the notebook PC, power is supplied from a power supply unit in the PCMCIA slot of the notebook PC instead of the AC / DC adapter, and communication control is performed from the notebook PC. Even in this case, the built-in battery can be charged while being inserted into the PCMCIA card slot of the PC and performing data communication by the above-described operation.

  In the above-described embodiment, when a mobile phone is used alone, it is possible to use a laminated type thin second (external) battery mounted on one surface of the mobile phone, etc., if necessary, and an external battery is attached. The size of the slot on the notebook PC side can be inserted even when the second battery is installed, or the mobile phone itself with the second battery is installed. By adjusting the size to the size of the notebook PC side slot, the built-in battery and the external battery can be charged with the second battery mounted. Of course, in this case as well, it is possible to use other AC / DC adapters for charging, and it is possible to charge the internal battery and the external battery as shown in FIG. 2 when the second battery is attached to the cellular phone. Needless to say, it can be configured as follows.

It is a figure which shows the structure of the mobile telephone as embodiment of this invention. It is a figure which shows the power supply component part of the mobile telephone of this Embodiment. It is a figure which shows the structure of other embodiment. It is a figure which shows the structure of the power supply and charging circuit by charging IC1. It is a figure which shows the structure of each regulator. It is a figure which shows the discharge characteristic of a lithium ion battery. It is a figure which shows the transition of discharge of an internal battery and an external battery, and battery operation | movement. It is a figure which shows other embodiment applied to the PHS apparatus of PCMCIA (TYPE2).

Explanation of symbols

1 Charging IC
2 Regulator 3 Battery switching circuit 4 Built-in battery 5 External battery 6 Charge switch 7 Battery connection terminals 31 and 32 P-type field effect transistors 33 and 34 Inverter circuit 35 Comparator
36 Pull-down resistor 37 AND circuit 61, 62 Switch 63 Operation section

Claims (6)

In a portable terminal device having a charging circuit connectable to a charging adapter, and a power supply line for supplying power from the charging circuit to the regulator,
An internal battery, a first switch connected between the output terminal of the internal battery and the power line, a battery connection terminal connectable to the output terminal of an external battery, the battery connection terminal and the power line A second switch connected between the battery switch and the battery connection terminal is controlled to turn on only the first switch when the voltage of the battery connection terminal is less than a predetermined reference voltage that is on or higher. A control circuit for first and second switches for controlling to the reference voltage state, and connecting the charging adapter to the charging circuit when power is supplied from the built-in battery or an external battery to a power line. Supply power to the regulator and select the internal battery or external battery via the first or second switch, respectively. Mobile terminal apparatus characterized in that it is charged. The third and fourth switches connected between the charging circuit and the power supply line and between the charging circuit and the battery connection terminal, and the on / off states of the third and fourth switches are opposite to each other. The mobile terminal device according to claim 1, further comprising: an operation unit that switches to The reference voltage is a low voltage alarm voltage value that is an input voltage of the regulator when outputting a minimum power supply voltage that can ensure operation characteristics of a circuit that operates with the output of the regulator. The portable terminal device described . In a portable terminal device having a charging circuit connectable to a charging adapter, and a power supply line for supplying power from the charging circuit to the regulator,
A third switch and a first switch connected in series between the charging circuit and the power supply line; a built-in battery having an output terminal connected to a connection point between the third switch and the first switch; A battery connection terminal connectable to the output terminal of the external battery; a second switch connected between the battery connection terminal and the power supply line; and a second switch connected between the charging circuit and the battery connection terminal. 4, the operation unit for switching the on and off states of the third and fourth switches in opposite directions, and the lowest power source that can ensure the operating characteristics of the circuit in which the voltage of the battery connection terminal operates with the output of the regulator When the voltage is equal to or higher than a low voltage alarm voltage value that is an input voltage of the regulator when outputting a voltage, only the second switch is controlled to be on, and the low voltage alarm voltage And a control circuit for controlling the first switch and the second switch to turn on only the first switch when the power is less than the power supply line, and supplying the charging adapter to the charging circuit when power is supplied from the built-in battery or the external battery to the power supply line. By connecting, power is supplied from the charging circuit to the regulator, and the built-in battery or the external battery can be selectively charged through the third or fourth switch, respectively. Terminal device. 5. A PCMCIA interface unit that can be inserted into a PCACIA card slot of a personal computer, and the charging circuit is connectable to a power source unit in the PCACIA card slot instead of a charging adapter. A portable terminal device according to any one of the above. 6. The portable terminal device according to claim 1, wherein the first and second switches are configured by MOS field effect transistors.

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