JPH0343298A - Ic memory card - Google Patents

Abstract

PURPOSE:To obtain an IC memory card constituted so that a battery can be replaced in such a state that a card is pulled out of external use machinery by providing a connection terminal part for a power supply different from the connection terminal part connectable to the connection part provided to the external use machinery. CONSTITUTION:A connection terminal part 105 for a power supply is mounted to the other terminal different from the connection terminal part 101 connectable to the connection part on the side of external use machinery. After the power of the outside is preliminarily supplied in such a state that a card is inserted in a set, the card is pulled out to make it possible to replace a battery with a new one and, therefore, a highly reliable IC memory card capable of memory backup is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an IC memory card with a built-in volatile memory (IJICt), and particularly to a memory backup structure when replacing the battery.

[Conventional technology]

Conventionally, there has been an IC memory card of this type as shown in FIG. That is, in the same figure, 101 is a connection terminal section with an external device, 102 is an IC memory card body, 103 is a memory backup battery housed in the IC memory card body 102, and 104 is a battery holder.

FIG. 3 is a block diagram showing the circuit configuration of this IC memory card. In the figure, 1 is a power supply switching circuit, and 2 is a volatile memo! JIC, 3 is a diode, 4 is a resistor, 5 is a primary battery, 6 is a capacitor, 7゜8 is the input terminal and output terminal of the power supply switching circuit 1, respectively, 9 is a power supply terminal, 10
1 is a ground terminal, and 11 is a detection terminal for externally monitoring the battery voltage.

Next, the operation will be explained.

In FIG. 2, the power supply switching circuit 1 opens the output terminal 8 when the level of the voltage applied to the input terminal 7 from the power supply terminal 9 is as low as a preset level (for example, about 4V). Become. When the set level is high, a voltage approximately equal to the voltage applied to the input terminal 7 is output from the output terminal 8. The input/output characteristics of the power supply switching circuit 1 described above are shown by the solid line in FIG.

Next, when the voltage applied to the input terminal 7 is lower than the preset voltage, the output terminal 8 is not opened, and the voltage 't-■ of the battery 5 and the current flowing into the memory IC 2 are Letting the voltage drops across diode 3 and resistor 4 caused by VD and vR, respectively, (VB-VD-VR)
A voltage appears.

-The voltage of the battery 5 is 3V, and the value of the resistor 4 is 1 and 5, respectively.
(1) The current flowing into the memory IC2 is several tens [μA
], then approximately 2.5 (V:
A voltage of about 1 appears. This situation is shown by the broken line in FIG.

Next, when carrying the memory card, in other words, power is not supplied to the power supply terminal 9, so the cand of diode 3 has approximately 2
．． A voltage of 5 (V) appears. When replacing the secondary battery 5 here, since the data retention voltage of the memo IJ IC is generally 2 [V] or more, the time that data is retained after the secondary battery 5 is removed is as follows. It is expressed by the formula.

Engineering: Bank amplifier current flowing to memory IC [A] C: Capacity of capacitor 6 [F] ■ = Memo IJ IC power supply voltage is approximately 2.5 (:V:]
to the data retention voltage [V] (here, 2.
5-2 = 0.5 [V)) Here, the bank up current of one memory IC is 1 [μA
] If the capacitance of the capacitor is 1 [μF], Memo IJ
If 10 ICs are installed, it will be 50 (m(3)), which is not practical at all.If the practical battery replacement time is 1 minute, the power supply and grounding of the memo IJ IC A capacitor of about 1000 [μF] is required between the terminals.However, a capacitor of about 1000CμF is required within the limited card dimensions.
] It is obvious that a capacitor of 100% or more cannot be inserted, considering the dimensions of current capacitors. Therefore, the current state is that power is being supplied to the power terminal of the card, that is,
The battery 5 is being replaced after inserting it into a device that reads and writes data in the memo IJIc. Incidentally, the battery voltage can be monitored by an external device other than the detection terminal 11.

[Problem to be solved by the invention]

Conventional IC memory cards are configured as described above, so the battery voltage inside the card is monitored by an external device and a warning is issued to the user when the battery voltage drops below a predetermined value. The most common way is to compare the battery voltage with a predetermined value (reference voltage) and output a binary signal indicating whether or not the battery needs to be replaced. It is something. In other words, since the battery voltage is not output as an analog quantity indicating how low the reference voltage is, the data may be lost as soon as the card is removed from the external device, so it must be replaced in the hole 1 where the card is inserted. This not only limits the design of external devices, but also causes problems such as inconvenience in replacing the card depending on where it is inserted.

This invention has been made to solve the above-mentioned problems, and its fifth objective is to provide an IC memory card whose battery can be replaced while the card is removed from an external device.

[Means to solve the problem]

The IC memory card according to the present invention is provided with a connection terminal section for power supply that is different from a connection terminal section connectable to a connection section provided on an external device.

[Effect]

Before removing the card from the external device, power is supplied to the connection terminal for power supply in advance and the button is pressed to back up the memory when the card is removed and replace the battery.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a perspective view of an IC memory card showing an embodiment of the present invention. In the figure, 1o1 is a connection terminal section for connecting to a connection section provided on an external device (hereinafter abbreviated as "Cent"), 102 is the RC memory card body, and 1o3 is a memory storage area when the Cento card is removed and carried. 104 is a battery holder for a memory bank up battery for holding data; and 105 is a power supply connection terminal for holding data in the memory in the card by supplying power from the outside.

The bank amplifier in the volatile memory in the card normally operates on the battery (when the card is carried or removed from the storage box) and determines whether it is depleted by setting a predetermined value (reference voltage... ...For example 2
．． 5V) and the battery voltage and output a binary signal indicating whether or not the battery needs to be replaced (warning the user). However, since the analog value of how low the battery voltage is compared to the reference voltage is not output, data may be lost as soon as the card is removed from the set. To prevent data loss, connect the connection terminal section 1 for power supply before removing the card.
Supply power to 05 in advance and press the button. Then remove the card and replace with a new battery.

〔Effect of the invention〕

As explained above, according to the present invention, since the connection terminal section for power supply is provided at the other end of the connection terminal section that is different from the connection terminal section that can be connected to the connection section (connector) on the set side, the card can be inserted into the set. This is an inexpensive, small-sized IC that allows you to remove the card and replace the battery with a new one while supplying external power in advance, making it possible to upgrade the memory bank with high reliability.
The extremely excellent effect of being able to provide a C memory card can be obtained.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the configuration of an IC memory card according to an embodiment of the present invention, FIG. 2 is a perspective view showing the configuration of a conventional IC memory card, and FIG. 3 is a block diagram of a conventional IC memory card. FIG. 4 is a diagram showing voltage characteristics of input/output terminals of a power supply switching circuit of a conventional IC memory card. 101...Connection terminal section with external equipment, 102.
...IC memory card body, 103...Battery for memory bank up, 104...Battery holder 10
5... Connection terminal section for power supply. Fig. 1 melon [V]

Claims (1)

[Claims] In an IC memory card having a built-in volatile memory IC, a backup battery for retaining information stored in the volatile memory IC, and a connection terminal section for connecting to an external device, the connection terminal section for power supply is provided. An IC memory card characterized by: