JPS63285692A - Ic card - Google Patents
Ic cardInfo
- Publication number
- JPS63285692A JPS63285692A JP62122023A JP12202387A JPS63285692A JP S63285692 A JPS63285692 A JP S63285692A JP 62122023 A JP62122023 A JP 62122023A JP 12202387 A JP12202387 A JP 12202387A JP S63285692 A JPS63285692 A JP S63285692A
- Authority
- JP
- Japan
- Prior art keywords
- power supply
- signal
- terminal
- card
- semiconductor element
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
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- 238000001514 detection method Methods 0.000 claims abstract description 52
- 239000004065 semiconductor Substances 0.000 claims abstract description 30
- 101100400378 Mus musculus Marveld2 gene Proteins 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 239000004020 conductor Substances 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
Landscapes
- Credit Cards Or The Like (AREA)
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Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
この発明は、電池によりバックアップされる半導体素子
をｂつＩＣカードの入力回路の改良に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement of an input circuit for an IC card having a semiconductor element backed up by a battery.
第２図は従来のＩＣカードの入力回路のブロック図で、
Ａは外部電源に接続される電源端子、Ｄは外部からチッ
プイネーブル信号やアドレス信号などが与えられる信号
端子であり、信号端子りは複数のうちの１つを代表的に
図示している。また１は電源端子Ａに接続され該電源端
子Ａの電圧値が一定値以上であると検出信号を出力する
電源電圧検出回路、２は電源電圧検出回路１からの信号
により電源の切り換えを行なう電源切り換え回路、３は
半導体素子をバックアップするため電源切り換え回路２
を介して半導体素子に接続された電池、４は電源切り換
え回路２を介して電源電圧を供給されまた信号端子りか
ら信号を受けて作動する半導体素子、５は信号端子りと
接地との間に接続されたプルダウン抵抗である。Figure 2 is a block diagram of the input circuit of a conventional IC card.
A is a power supply terminal connected to an external power supply, and D is a signal terminal to which a chip enable signal, an address signal, etc. are applied from the outside, and one of the plurality of signal terminals is representatively shown. Further, 1 is a power supply voltage detection circuit that is connected to power supply terminal A and outputs a detection signal when the voltage value of power supply terminal A is above a certain value, and 2 is a power supply that switches the power supply according to the signal from power supply voltage detection circuit 1. Switching circuit 3 is a power supply switching circuit 2 to back up the semiconductor element.
4 is a semiconductor element which is supplied with power supply voltage through the power supply switching circuit 2 and operates by receiving a signal from a signal terminal; 5 is a battery connected between the signal terminal and ground; Connected pull-down resistor.
従来のＩＣカードの入力回路は上記のように構成されて
いる。そして一般にＩＣカードが使用される場合、外部
機器と接続される。以下、ＩＣカードを外部ｖｓ、器に
接続した場合と外部機器に接続しない場合について説明
する。The input circuit of a conventional IC card is configured as described above. Generally, when an IC card is used, it is connected to an external device. Below, a case where the IC card is connected to an external device and a case where the IC card is not connected to an external device will be explained.
まずＩＣカードを外部機器に接続した場合について説明
する。この場合、電ａ端子へに外部機器から電圧が供給
されるため、電源端子への電圧が電源電圧検出回路１の
検出電圧以上となる。そのため電源電圧検出回路１から
検出信号が出力される。そしてその検出信号が電源切り
換え回路２に入力され電源の切り換えが行なわれ、半導
体素子４の電源は電ｍ 端子Ａから供給される。またこ
の場合、半導体素子４の信号端ＦＤにも外部機器からチ
ップイネーブル信号やアドレス信号などが与えられる。First, the case where the IC card is connected to an external device will be explained. In this case, since voltage is supplied to the power terminal A from the external device, the voltage to the power supply terminal becomes higher than the detection voltage of the power supply voltage detection circuit 1. Therefore, a detection signal is output from the power supply voltage detection circuit 1. Then, the detection signal is input to the power supply switching circuit 2 to switch the power supply, and the power to the semiconductor element 4 is supplied from the electric terminal A. Further, in this case, a chip enable signal, an address signal, etc. are also applied to the signal terminal FD of the semiconductor element 4 from an external device.
そして、゛ト導体素Ｆ４（例えばスタティックＲＡＭ）
は作動し、データの占込みや読出しが行なわれる。この
ときプルダウン抵抗５は、信号端子りに接続されたまま
である。And conductor element F4 (for example, static RAM)
is activated, and data is inserted and read. At this time, the pull-down resistor 5 remains connected to the signal terminal.
次にＩＣカードを外部機器に接続しない場合について説
明する。この場合、電源端子Ａには外部機器から電圧が
供給されないため、電源端子Ａの電圧は、電源電圧検出
回路１の検出電圧以下となる。そのため電源電圧検出回
路１からは検出信号が出力されない。従って電源切り換
え回路２に検出信号が入力されず、半導体素子４の電源
電圧は、半導体素子４をバックアップするための電池３
により供給される。またＩＣカードが外部機器に接続さ
れていない場合、半導体素子４の信号端子りには外部機
器から信号は供給され、ない。従って、半導体素子４は
作動しない。この場合プルダウン抵抗５は、信号端子り
の電位を接地レベルにプルダウンしている。Next, a case where the IC card is not connected to an external device will be explained. In this case, since no voltage is supplied to the power supply terminal A from the external device, the voltage of the power supply terminal A is equal to or lower than the detection voltage of the power supply voltage detection circuit 1. Therefore, the power supply voltage detection circuit 1 does not output a detection signal. Therefore, no detection signal is input to the power supply switching circuit 2, and the power supply voltage of the semiconductor element 4 is changed to the battery 3 for backing up the semiconductor element 4.
Powered by. Further, when the IC card is not connected to an external device, no signal is supplied from the external device to the signal terminal of the semiconductor element 4. Therefore, the semiconductor element 4 does not operate. In this case, the pull-down resistor 5 pulls down the potential of the signal terminal to the ground level.
従来のＩＣカードは以上のように構成されており、ＩＣ
カードを外部機器に接続した場合、つまり半導体素子４
の制御端子りに電圧がかかった場合、プルダウン抵抗５
は常に半導体素子４の信号＠ｆＦＤに接続されているた
め、プルダウン抵抗５が半導体素子４の信号端子りから
の入力電流を必ず消費するという問題があった。−例と
してプルダウン抵抗５の抵抗値が１０にΩ程度のときに
はプルダウン抵抗５には５００μ八程度の電流が流れる
ことになる。特にＩＣカード使用時に接続される外部機
器の電源が電池の場合、プルダウン抵抗５が半導体素子
４の信号端子りからの入力電流を消費すると、外部機器
の電源である電池の寿命が短くなり不便である。Conventional IC cards are configured as described above, and the IC
When the card is connected to an external device, that is, the semiconductor element 4
When voltage is applied to the control terminal of
Since it is always connected to the signal @fFD of the semiconductor element 4, there is a problem that the pull-down resistor 5 always consumes the input current from the signal terminal of the semiconductor element 4. - For example, when the resistance value of the pull-down resistor 5 is about 10Ω, a current of about 500 μ8 will flow through the pull-down resistor 5. Especially when the power source of the external device connected when using an IC card is a battery, if the pull-down resistor 5 consumes the input current from the signal terminal of the semiconductor element 4, the life of the battery that is the power source of the external device will be shortened, which is inconvenient. be.
この発明は、従来のＩＣカードにおける上述の問題点を
解決するためになされたもので、内蔵のスタティックＲ
ＡＭ等の半導体素子の信号端子に電圧がかかったときに
該信号端子からの入力電流を減少させ、外部機器の電源
が電池の場合にその電池を無用に消費することのないＩ
Ｃカードを提供することを目的とするものである。This invention was made in order to solve the above-mentioned problems with conventional IC cards.
When a voltage is applied to the signal terminal of a semiconductor element such as an AM, the input current from the signal terminal is reduced, and when the power source of an external device is a battery, the battery is not consumed unnecessarily.
The purpose is to provide C cards.
本発明に係るＩＣカードは、外部電源に接続される電源
端子と、前記電源供給端子に接続され、この電源端子の
電圧値が一定値以上であると検出信号を出力する電源電
圧検出回路と、バックアップ用電源としての電池と、前
記電源電圧検出回路からの検出信号の有無に応じ前記外
部電源／前記電池の切り換えを行なう電源切り換え回路
と、外部と所定の信号の授受を行なう信号端子と、前記
電源切り換え回路を介して電源電圧を供給されまた前記
信号端子から信号を受けて作動する半導体素子と、前記
信号端子と所定電位との間に接続され、前記電源電圧検
出回路からの検出信号に応答して非導通する電気的スイ
ッチとを設けている。An IC card according to the present invention includes: a power supply terminal connected to an external power supply; a power supply voltage detection circuit connected to the power supply terminal and outputting a detection signal when the voltage value of the power supply terminal is equal to or higher than a certain value; a battery as a backup power source; a power supply switching circuit that switches between the external power source and the battery depending on the presence or absence of a detection signal from the power supply voltage detection circuit; a signal terminal that exchanges a predetermined signal with the outside; A semiconductor element that is supplied with a power supply voltage via a power supply switching circuit and operates upon receiving a signal from the signal terminal, and a semiconductor element that is connected between the signal terminal and a predetermined potential and responds to a detection signal from the power supply voltage detection circuit. An electrical switch is provided to make the switch conductive.
この発明における電気的スイッチは、電源電圧検出回路
の検出信号に応答して実導通する。従って、ＩＣカード
使用時にＩＣカードを外部機器に接続した場合、つまり
半導体素子の信号端子に電圧がかかった場合、該信＠端
子を所定電位から電気的に切り離すことができ、所定電
位の側へは電流は流れない。また電源電圧検出回路が検
出信号を出力しないときは電気的スイッチは導通し、信
号端子は所定電位にプルダウンまたはプルアップされる
。The electrical switch in the present invention becomes conductive in response to a detection signal from a power supply voltage detection circuit. Therefore, when the IC card is connected to an external device when using the IC card, that is, when a voltage is applied to the signal terminal of the semiconductor element, the signal terminal can be electrically disconnected from the predetermined potential and transferred to the side of the predetermined potential. No current flows. Further, when the power supply voltage detection circuit does not output a detection signal, the electric switch is turned on and the signal terminal is pulled down or pulled up to a predetermined potential.
第１図は、この発明によるＩＣカードの一実施例におけ
る入力回路を示すブロック図である。FIG. 1 is a block diagram showing an input circuit in an embodiment of an IC card according to the present invention.
同図において、６はプルダウン抵抗５と接地との間に接
続され、電源電圧検出回路１からの検出信号が入力され
ることにより非導通し、プルダウン抵抗５をＩＣカード
の信Ｓ ｙｕ子から電気的に切り離す電気的スイッチで
ある。その他の構成は前記した従来のＩＣカードの入力
回路と全く同一であるので説明を省略する。In the same figure, 6 is connected between the pull-down resistor 5 and the ground, and becomes non-conductive when the detection signal from the power supply voltage detection circuit 1 is input, and the pull-down resistor 5 is connected to the input terminal of the IC card. It is an electrical switch that disconnects the The rest of the configuration is exactly the same as the input circuit of the conventional IC card described above, so the explanation will be omitted.
次に動作について、ＩＣカードを外部機器に接続した場
合と外部機器に接続しない場合について説明する。Next, the operation will be described with respect to a case where the IC card is connected to an external device and a case where the IC card is not connected to an external device.
まずＩＣカードを外部機器に接続した場合について説明
する。この場合、電ｍ端子Ａに外部機器から電圧が供給
されるため、電源端子Ａの電圧が電源電圧検出回路１の
検出電圧以上となる。そのため、電源電圧検出回路１か
ら検出信号が出力される。そして、その信号が電気的ス
イッチ６に入力され、この電気的スイッチ６は非導通と
なる。First, the case where the IC card is connected to an external device will be explained. In this case, since the voltage is supplied to the power terminal A from the external device, the voltage at the power supply terminal A becomes equal to or higher than the detection voltage of the power supply voltage detection circuit 1. Therefore, a detection signal is output from the power supply voltage detection circuit 1. Then, the signal is input to the electrical switch 6, and the electrical switch 6 becomes non-conductive.
従って、半導体素子４の信号端子りと電気的スイッチ６
との間に接続されたプルダウン抵抗５は、ＩＣカードの
入力回路から電気的に切り離された状態になる。そのた
めＩＣカードが外部機器に接続された状態で、半導体素
子４の信号端子りにチップセレクト信号やアドレス信号
などが与えられ、信号端子りから入力電流が流入しても
プルダウン抵抗５が当該入力電流を無用に消費すること
はない。Therefore, the signal terminal of the semiconductor element 4 and the electrical switch 6
The pull-down resistor 5 connected between the two is electrically disconnected from the input circuit of the IC card. Therefore, when the IC card is connected to an external device, a chip select signal, an address signal, etc. are applied to the signal terminal of the semiconductor element 4, and even if an input current flows from the signal terminal, the pull-down resistor 5 will not be consumed unnecessarily.
次にＩＣＣカード番外線機器接続しない場合について説
明する。この場合、電源端子Ａには外部機器から電圧が
供給されないため、電源端子Ａの電圧は、電源電圧検出
回路１の検出電圧以下となる。そのため、電源電圧検出
回路１からは検出信号が出力されない。従って電気的ス
イッチ６には電源電圧検出回路１からの検出信号は入力
されず、電気的スイッチ６は導通する。そして、半導体
素子４の信号端子りはプルダウン抵抗５を介して接地レ
ベルにプルダウンされる。ＩＣカードが外部機器に接続
されていないため、半導体素子４の信号端子りには信号
が与えられることはなく、プルダウン抵抗５による電流
消費の問題は生じない。Next, a case where the ICC card is not connected to an extra line device will be explained. In this case, since no voltage is supplied to the power supply terminal A from the external device, the voltage at the power supply terminal A is equal to or lower than the detection voltage of the power supply voltage detection circuit 1. Therefore, the power supply voltage detection circuit 1 does not output a detection signal. Therefore, the detection signal from the power supply voltage detection circuit 1 is not inputted to the electrical switch 6, and the electrical switch 6 becomes conductive. The signal terminal of the semiconductor element 4 is pulled down to the ground level via the pull-down resistor 5. Since the IC card is not connected to an external device, no signal is applied to the signal terminal of the semiconductor element 4, and the problem of current consumption by the pull-down resistor 5 does not occur.
なお、上記実施例においては、プルダウン抵抗５を用い
た場合について説明したが、プルアップ抵抗でもよく、
また抵抗を用いずに電気的スイッチ６を介して直接に所
定電位に接続する場合でも同様の動作が実現できる。In addition, in the above embodiment, the case where the pull-down resistor 5 was used was explained, but a pull-up resistor may also be used.
Further, the same operation can be realized even when connecting directly to a predetermined potential via the electrical switch 6 without using a resistor.
また、上記実施例では、電気的スイッチ６が、電池３に
よりバックアップされている半導体素子４とは別々に記
載されているが、これらは１つの半導体素子内で実現す
ることも可能である。この場合においては、ＩＣカード
の入力回路の小型化も期待できる。Further, in the above embodiment, the electrical switch 6 is described separately from the semiconductor element 4 backed up by the battery 3, but these can also be realized within one semiconductor element. In this case, the input circuit of the IC card can also be expected to be miniaturized.
以上説明したように、この発明によれば、電源電圧検出
回路からの検出信号の入力により非導通する電気的スイ
ッチを信号端子と所定電位との間に接続しているため、
ＩＣカードが外部機器に接続され、電源端子に電源電圧
検出回路の検出電圧以上の電圧が供給される通常の動作
電源電圧範囲では、電源電圧検出回路からの検出信号が
電気的スイッチに入力されて電気的スイッチは非導通と
なり、信号端子は所定電位から電気的に切り離される。As explained above, according to the present invention, since the electrical switch that becomes non-conductive upon input of the detection signal from the power supply voltage detection circuit is connected between the signal terminal and the predetermined potential,
In the normal operating power supply voltage range when the IC card is connected to an external device and a voltage higher than the detection voltage of the power supply voltage detection circuit is supplied to the power supply terminal, the detection signal from the power supply voltage detection circuit is input to the electrical switch. The electrical switch becomes non-conductive and the signal terminal is electrically disconnected from the predetermined potential.
このため半導体素子の信号端子に電圧がかかつているＩ
Ｃカードの通常動作範囲では、半導体素子の信号端子か
ら所定電位の側に無用の電流が流れることがなく、外部
機器からの入力電流を減少させることができるという効
果がある。Therefore, a voltage is applied to the signal terminal of the semiconductor element.
In the normal operating range of the C card, unnecessary current does not flow from the signal terminal of the semiconductor element to the side of the predetermined potential, which has the effect of reducing the input current from external equipment.
第１図はこの発明の一実施例を示すブロック図、第２図
は従来のＩＣカードの入力回路を示すブロック図である
。
図において、Ａは電源端子、Ｄは信号端子、１は電源電
圧検出回路、２は電源切り換え回路、３は電池、４は半
導体素子、５はプルダウン抵抗、６は電気的スイッチで
ある。
なお、各図中同一符号は同一または相当部分を示す。FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing an input circuit of a conventional IC card. In the figure, A is a power supply terminal, D is a signal terminal, 1 is a power supply voltage detection circuit, 2 is a power supply switching circuit, 3 is a battery, 4 is a semiconductor element, 5 is a pull-down resistor, and 6 is an electrical switch. Note that the same reference numerals in each figure indicate the same or corresponding parts.
Claims (2)
一定値以上であると検出信号を出力する電源電圧検出回
路と、 バックアップ用電源としての電池と、 前記電源電圧検出回路からの検出信号の有無に応じ前記
外部電源／前記電池の切り換えを行なう電源切り換え回
路と、 外部と所定の信号の授受を行なう信号端子と、前記電源
切り換え回路を介して電源電圧を供給されまた前記信号
端子から信号を受けて作動する半導体素子と、 前記信号端子と所定電位との間に接続され、前記電源電
圧検出回路からの検出信号に応答して非導通する電気的
スイッチとを備えたＩＣカード。(1) A power supply terminal connected to an external power supply; a power supply voltage detection circuit connected to the power supply terminal and outputting a detection signal when the voltage value of the power supply terminal is above a certain value; and a power supply voltage detection circuit as a backup power supply. a battery; a power supply switching circuit that switches between the external power supply and the battery depending on the presence or absence of a detection signal from the power supply voltage detection circuit; a signal terminal that transmits and receives a predetermined signal to and from the outside; a semiconductor element that is supplied with a power supply voltage and operates upon receiving a signal from the signal terminal; and a semiconductor element that is connected between the signal terminal and a predetermined potential and becomes non-conductive in response to a detection signal from the power supply voltage detection circuit. An IC card equipped with an electric switch.
ッチと直列に抵抗を接続した、特許請求の範囲第１項記
載のＩＣカード。(2) The IC card according to claim 1, further comprising a resistor connected in series with the electrical switch between the signal terminal and a predetermined potential.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62122023A JP2508085B2 (en) | 1987-05-19 | 1987-05-19 | IC card |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62122023A JP2508085B2 (en) | 1987-05-19 | 1987-05-19 | IC card |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63285692A true JPS63285692A (en) | 1988-11-22 |
| JP2508085B2 JP2508085B2 (en) | 1996-06-19 |
Family
ID=14825674
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62122023A Expired - Lifetime JP2508085B2 (en) | 1987-05-19 | 1987-05-19 | IC card |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2508085B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS647186A (en) * | 1987-06-29 | 1989-01-11 | Nec Corp | Ic card |
-
1987
- 1987-05-19 JP JP62122023A patent/JP2508085B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS647186A (en) * | 1987-06-29 | 1989-01-11 | Nec Corp | Ic card |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2508085B2 (en) | 1996-06-19 |
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