JPS63270194A - Portable memory medium - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Purpose of the Invention (Industrial Application Field) The present invention relates to a portable storage medium such as an IC card (prior art). Tori, No. 9
No figure, 11th floor! 4 will be used for explanation.

The IC card 30 includes, for example, a CPU block 21 and an E
A small printing plate 23 on which both IC (integrated circuit) chips 22 of a memory chip 22 such as EIIROM are mounted.
is pushed into a plastic card base material 24, and the CPU chip 21 and memory depth 2 are placed on its surface.
2 and a power terminal 25a1 for connection with an external device such as a reading/writing device, which will be described later, and a grounding terminal 25e.
A plurality of external terminals 25, such as the cock signal terminal 25b1, the reset terminal 25c, and the input/output terminal 250, are removed.

Then, the IC card 30 is inserted into a reading/writing device 26 as shown in FIG. 1l
The III11 circuit 28 reads and stores required data into the memory 22.

(Problems to be Solved by the Invention) In the IC card 30, the external terminals 25 connected to IC chips such as the CPU chip 21 and the memory chip 22 are exposed on the surface of the card base material 24. If a charged human hand or the like touches the IC chip, the static electricity may destroy the IC chip. Also, the IC card 30 is inserted into the reading/writing device 26, and 1
When power supply voltage is being supplied from the JJI11 circuit 28 to the IC card 30 via the cable 29 and contacts 27, etc., when N source noise is induced from the outside in the cable 29, etc., or when a surge etc. enters the power supply current. When the power supply voltage fluctuates due to a voltage drop due to impedance at the cable 29, contact 27, etc., malfunctions may occur in reading, outputting, etc.

To deal with this, measures have been taken such as connecting a bypass capacitor to the control circuit 288g on the read/write device 26 side to bypass the N source noise, but this is not sufficient. .

The present invention has been made based on the above circumstances, and an object of the present invention is to provide a portable storage medium that is resistant to power supply noise and static electricity and can avoid increased safety.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above problems, the present invention provides a plurality of external terminals including a power terminal and a ground terminal for electrical connection with the external Vt stomach. and an integrated circuit chip connected to the plurality of external terminals,
The main feature is that the power supply terminal includes a bypass capacitor connected to the power terminal and the ground terminal, and a surge absorption element connected between each external terminal except the ground terminal and the ground terminal.

(Function) Even if noise occurs on the power line while power is being supplied from an external device through the external terminal, the bypass capacitor connected between the Ti source terminal and the ground terminal will prevent the power supply noise from affecting the integrated circuit chip. Effects are properly removed. In addition, even if a charged person's hand touches the external terminal when carrying the device, the electrostatic surge will be properly absorbed by the connection between each external terminal except the ground terminal and the ground terminal. Ru.

(Example) Hereinafter, an example of the present invention will be described based on the drawings. This embodiment is applied to an IC card.

1 to 5 are diagrams showing a first embodiment of the present invention.

First, the configuration of the IC card 10, which is a portable storage medium, will be explained.
1 memory in 1 chip! A small printing board module 4, on which the integrated LSII, bypass capacitor 2, and surge absorbing element chip 3 are mounted and connected as required by wire bonding, is embedded in a plastic card base material 5, and on its surface, A plurality of external terminals 6 are provided, such as a power supply terminal 6a, a ground terminal 6e, a clock signal terminal 6b, a reset terminal 6C, and an input/output terminal 6d.

The bypass capacitor 2 is, for example, a thin and small one, and the number absorption element chip 3 includes one common Zener diode 3a and a common Zener diode 38, as shown in FIG. Other four Zener diodes 3b and 3c1 commonly connected in reverse direction to the anode.
It is composed of 3d and 3er. These Zener diodes 3a to 3e as surge absorbing elements
As shown in the figure, the common Zener diode 3a is placed almost in the center, and the other four Zener diodes 3b, 3 are placed around it.
It is composed of one chip so that c, 3d13e are worth the weight.

As mentioned above, the CPU and the memory are integrated into one chip LS11, the bypass capacitor 2 is formed into a small B type, and the multiple Zener diodes 3a to 3C are integrated into one chip as the resistance absorbing element chip 3. , these are appropriately mounted on the printing plate Modicoll 4'' and can be embedded in the card base material 5.

The bypass capacitor 2 is connected between the power supply terminal 6a and the ground terminal 6e, and the cathode of the common Zener diode 3a in the surge absorbing element deep 3 is connected to the ground terminal 6e, and the cathode of the common Zener diode 3a in the surge absorbing element deep 3 is connected to the ground terminal 6e.
, 3c, 3d, and 3e are connected to a power supply terminal 6a, a clock signal terminal 6b, a reset terminal 6C, and an input/output terminal 6d, respectively.

Next, the action will be explained.

The IC card 10 is inserted into a reading/writing device as shown in FIG.
The IIJt11 circuit reads and writes required data to and from the memory in the LSII. During such operation, power supply noise is induced in the cable between the read/write v4M control circuit and the IC card 10, or a surge or the like enters the power supply current, causing contact between the contacts and the external terminal 6. Voltage drops due to resistors etc. cause fluctuations in the power supply voltage f[C, but these power supply noises and voltage fluctuations are absorbed by the bypass capacitor 2,
Stability of operation is achieved.

Furthermore, even if a charged human hand touches the external terminal 6 while carrying the device and static electricity is discharged to any of the other PIS E elements 6, the electrostatic surge caused by this discharge will be absorbed by the zener, which is a nozzle absorption element. It is absorbed by the diodes 38 to 3e to prevent destruction of the LSII.

In a conventional IC card without a surge absorbing element, the static electricity resistance was limited to 1.5KV due to the withstand voltage of the LSII itself, but in this embodiment, it can be increased to about 10 to 20KV. F.

Depending on the type of IC card, there are some that require a write voltage ■pp in addition to the power supply voltage ycc, but in the case of such IC cards, the connection between the external terminal to which Vpp is input and the ground terminal is A bypass capacitor is also connected between them. In addition to the avalanche breakdown Zener diode described above, a varistor type element can also be used as the surge absorbing element.

Next, FIGS. 6 and 7 show a second embodiment of the present invention. In this embodiment, the IC chip is the CPU chip 11.
The present invention is applied to a device configured with two bootstubs, ie, a memory chip 12 and a memory chip 12.

Even if the IC chip is composed of two chips, each chip can be sufficiently miniaturized.
1. The memory chip 12, the bypass capacitor 2, and the surge absorbing element chip 3 can be appropriately mounted on the small printing board module 14, and these card base materials 5
It is possible to embed it into. The manner in which the bypass capacitor 2 and the surge absorbing element chip 3 are connected to the external terminal 6 and their effects are substantially the same as those in the first embodiment.

FIG. 8 shows a third embodiment of the invention. In this embodiment, the present invention is applied to a multifunctional IC card 20 equipped with a keyboard 15 and an LCD display 16. The manner in which the bypass capacitor and the surge absorbing element chip are connected to the external terminal 6 and their effects are substantially the same as those described later in the first real IM@.

[Effects of the Invention] As explained above, according to the present invention, the effect of external power supply noise on the integrated circuit chip is removed by the bypass capacitor connected between the power supply terminal and the ground terminal, and the effect of external power supply noise on the integrated circuit chip is removed. Since electrostatic surges are absorbed by the voltage absorbing element connected between each external terminal except for .

[Brief explanation of the drawing]

1 to 5 show a first embodiment of a portable storage medium according to the present invention, and FIG. 1 is an internal circuit diagram, and FIG.
The figure is a plan view, FIG. 3 is a diagram showing a printing board module on which an integrated circuit chip is mounted, FIG. 4 is a circuit diagram of a surge absorbing element chip, FIG. 5 is a plan view of the same surge absorbing element chip, and FIG. The figure is an internal circuit diagram showing a second embodiment of the invention, FIG. 7 is a plan view showing a printing plate module applied to the circumferential WI2 embodiment, and FIG. 8 is a plan view showing a third embodiment of the invention. 9 to 11 show a conventional portable storage medium, in which FIG. 9 is an internal circuit diagram, FIG. 10 is a plan view, FIG. 11 is a diagram showing a printing board module, and FIG. 12 is a diagram showing a conventional portable storage medium. 13 is a perspective view of a reading/writing device into which a portable storage medium is inserted, and FIG. 13 is a block diagram partially showing the inside of the reading/writing device. 1: LSI (integrated circuit chip), 2: Bypass capacitor, 3: Surge absorption element chip, 6: External terminal, 6a: Power supply terminal, 6e: Ground terminal, 10.20: IG card (portable storage medium), 11 :
CPU chip (integrated circuit chip), 12: memory chip (integrated circuit chip).

Claims (1)

[Scope of Claims] A portable storage medium having a plurality of external terminals including a power terminal and a ground terminal for electrically connecting with an external device, and an integrated circuit chip connected to the plurality of external terminals. , a portable device comprising: a bypass capacitor connected between the power supply terminal and the ground terminal; and a surge absorption element connected between each external terminal other than the ground terminal and the ground terminal. storage medium.