JPS6231225A - Portable type radio transmitter/receiver - Google Patents

Abstract

PURPOSE:To suppress current consumption and to obtain a radio set with a high output by operating a power supply switch so that the drain and source of a MOSFET are connected to the 1st power supply and a transmitting/ receiving part respectively and its gate is connected to the 2nd power supply through the switch. CONSTITUTION:An N-channel enhancement type MOSFET 11 is used, its drain D is connected to the 1st battery 13 through a terminal 12, its source S is con nected to a radio transmitting/receiving part 3, and its gate G is connected to the 2nd battery 16 through the operation switch 14 and a terminal 15. When the operation switch 14 is turned on, the voltage of the 2nd battery 16 is applied to the gate G of the FET 11. The voltage application turns on the drain-source of the FET 11, so that electric power is supplied from the battery 13 to the transmitting/receiving part 3. In this case, a gate driving current is slight current <=1mA.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a portable wireless transceiver, and particularly to a power switch thereof.

[Conventional technology]

2. Description of the Related Art In recent years, in the fields of portable personal radios for mobile communications, car telephones, and the like, there has been a demand for higher output radio equipment in order to expand service areas. An unavoidable problem that arises with this increase in output is an increase in current consumption. For example, in order to obtain a transmission output of 5 W in the 800 MHz band, two to three people will need electric current. If this current is to be passed through the battery and the radio section of a portable radio, the power switch between them will also need to have a corresponding passing current tolerance.

A power switch conventionally used in this type of portable radio device is shown in FIGS. 2 and 3.

In FIG. 1, reference numeral 1 denotes a battery as a power source, which is connected to a transmitter/receiver section 3 via a power operation switch 2. In FIG. The switch 2 is a mechanical switch such as a toggle switch or a rotary switch, and when transmitting with this switch turned on, the transmission output is radiated from the transmitting/receiving section 3. In this case, if the transmission output is high, it is necessary to supply a corresponding transmission current from the battery 1, but since this transmission current passes through the switch 2, the permissible current value must be greater than the transmission current. Become. That is, the transmission current is 2 to 3
If A, the allowable current value of the switch 2 is also 2 to 3 A.
That's all.

On the other hand, in FIG. 3, an electronic switch 4 such as a relay or a bipolar transistor is used in place of the power supply operation switch 2, and this is operated by an operation switch 5. In FIG.

[Problem that the invention seeks to solve]

However, if a toggle switch or a rotary switch is used that satisfies the above-mentioned allowable current value, the switch will inevitably have a large external size and a large operating section. This is an inconvenience in portable radio devices, which are pursuing miniaturization.

In this respect, in the case shown in FIG. 3, compared to the case shown in FIG. 2, since no transmission current is passed through the operation switch, a compact radio device can be obtained.

However, on the other hand, since the electronic switch 4 is driven even during standby and reception, the driving current is constantly flowing, which is said to shorten the operating time of the portable radio. causing inconvenience.

[Means for solving problems]

In order to solve these problems, the present invention inserts an N-channel enhancement type MOS FET into the power supply line to the transmitter/receiver, and connects its drain to the first power supply and the source to the transmitter/receiver. Along with connecting,
The gate is connected to a second power supply via a switch.

[Effect]

By turning on the switch, the voltage of the second power supply is applied to the gate of the 9 MOS FET, the source and drain become conductive, and the first power supply is connected to the transmitting/receiving section.

〔Example〕

FIG. 1 is a block diagram showing one embodiment of the present invention. In the same figure, an N-channel enhancement type MOS FET is used instead of the switch 2.4 in FIGS. 2 and 3.
11, its drain D is connected to the first battery 13 through the terminal 12, the source S is connected to the wireless transmitter/receiver 3, and the source G is connected to the second battery through the operation switch 14 and the terminal 15. It is connected to the battery 16. In addition,
The pull-down circuit 1T connected to the FET 11 is a ground circuit made of a resistor or the like, and serves as a protection circuit for the FET 11.

Further, the voltage value v2 of the second battery 16 is the same as that of the first battery 13.
The voltage value v1 is also set to a sufficiently large value.

This is to make the gate-source voltage VGS equal to vG6>o when the FET 11 is on.

In the above configuration, when the operation switch 14 is turned on, F
The voltage v2 of the second battery 16 is applied to the gate (G) of KTll. By applying this voltage, the drain of FET11
When the source is turned on, power is supplied to the transmitting/receiving section 3 from the battery 13.

In this case, due to the characteristics of the MOS FET, the gate drive current is a very small current of 1 mA or less. This value is
This value is extremely small compared to the conventional example shown in FIG.

Therefore, the battery capacity of the second battery 16 only needs to be small, and an ultra-small battery can be used. In addition, operation switch 1
4 can also be used as a compact one with an allowable current value of several mA. The MOS FETI I itself is also easily available in a small size and with a large tolerance for the passage of the transmission am.

〔Effect of the invention〕

As explained above, according to the present invention, an N-channel enhancement type MO
Insert an SFET, connect its drain to the first power supply, source to the transmitting/receiving section, and connect the gate to the second through a switch.
It is possible to obtain a portable radio transmitter/receiver having a negligible drive current, i.e., extremely low consumption ti, and having a compact power switch circuit. This is extremely useful especially when increasing the output of a portable radio device.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIGS. 2 and 3 are block diagrams showing conventional examples, respectively. 3... Transmitter/receiver section, 11... N-channel enhancement type MOSFET, 13... First battery, 14... Operation switch, 16... Second battery . Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] In a portable wireless transmitter/receiver equipped with a transmitting/receiving section and a power supply circuit, N is connected to the power supply line from the first power source to the transmitting/receiving section.
A channel enhancement type MOS FET is inserted, the drain of the MOS FET is connected to a first power source, the source is connected to a transmitting/receiving section, and the gate is connected to a second power source via a switch. Portable wireless transceiver.