JPS6336319A - Backup of ic memory - Google Patents

Abstract

PURPOSE:To stably supply an IC memory holding voltage in response to a voltage drop of a system power source, by using a secondary battery in which an electrode active material of at least one of the negative pole and the positive pole consists of a conductive high polymer material, as a battery power source. CONSTITUTION:By using a secondary battery in which an electrode active material of at least one of the negative pole and the positive pole consists of a conductive high polymer material, as a battery power source 3, a holding voltage of an IC memory 4 of >=about 2.0V can be supplied by a single secondary battery. Also, since there is a corresponding relation between the battery voltage and the battery capacity, the available period up to the limit for supplying the holding voltage of the memory 4 without a hindrance can be known easily. As for the conductive high polymer material, by using polyaniline, a secondary battery whose battery capacity per electrode active material is large, and also, which is excellent in a repetitive characteristic of charge/discharge is obtained.

Description

[Detailed description of the invention] The present invention includes a system power source and a battery power source,
IC memory that quickly responds to a voltage drop in the system power supply in the event of a power cut or other system power failure, switches to the system power supply, activates the battery power supply, and retains the stored memory contents. Regarding backup.

Conventional technology Personal computers and electronic devices based on them, such as game machines, word processors, and facsimile machines, have appropriate memory functions such as buffer memory and page memory that can temporarily input and store electrical signals and clear them when not needed. needed.

For this reason, IC memories such as CMO3RAM are used.

An IC memory such as the CMO3RAM mentioned above that can temporarily input and store electricity (No. 2) and clear it when unnecessary (hereinafter referred to as
Since IC memory (IC memory) is volatile, unlike non-volatile memory such as floppy disks and magnetic tape,
In order to retain the memory contents, it is necessary to stably supply a desired voltage, and this voltage is normally supplied by the system power supply. In order to preserve the memory contents even in the event of a system power failure, an IC memory backup is used with the IC memory, which is equipped with a battery power source that can quickly switch over to the system source and supply a stable desired voltage. .

Conventionally, a nickel-cadmium secondary battery has been used as a battery power source for the above-mentioned IC memory backup.

However, the output of nickel-cadmium secondary batteries is
If the voltage is approximately 1.3V and it is used as a battery power source for IC memory backup, the holding voltage (memory holding voltage) required to retain the memory contents of the IC memory is approximately 2.0V or more. In some cases, an output voltage that takes into account the voltage drop caused by diodes, etc. is required, so it is necessary to arrange two or three nickel-cadmium secondary batteries in series, which reduces the space occupied by the battery power source. There was a problem with that. Furthermore, nickel-cadmium secondary batteries have very good battery voltage flatness, so the voltage hardly changes even when the battery capacity is low. Therefore, when nickel-cadmium batteries are used as a battery power source for IC memory backup, Often, because the timing of charging is missed, the battery power supply voltage suddenly drops suddenly during backup, and the voltage drops below the memory retention voltage of the IC memory, causing problems such as the inability to retain the stored memory contents. There was fear.

On the other hand, although lithium batteries are commercially available as batteries with a high output voltage, they are secondary batteries and cannot be reused by charging, which is inconvenient as a battery power source.

The present invention was made in view of the above circumstances, and is designed to prevent power outages or other abnormalities when a power failure occurs in the system.
Approximately 2. I above OV
The purpose of the present invention is to provide a compact IC memory backup capable of stably supplying C memory holding voltage.

In order to achieve the above object, the IC memory backup of the present invention is equipped with a system power source and a battery power source,
When the system power supply voltage drops.

In the IC memory backup, the stored contents of the IC memory are retained by stopping the voltage supply from the system power supply in response to a drop in the system power supply voltage, and by operating the battery power supply to supply voltage. As a battery power source, a secondary battery is used in which the electrode active material of at least one of the negative electrode and the positive electrode is a conductive polymer material, preferably polyaniline.

Kita■ The IC memory backup of the present invention uses a secondary battery in which at least one of the negative electrode and the positive electrode active material is made of a conductive polymer material as a battery power source. The holding voltage can be supplied by a single secondary battery, and secondary batteries that use conductive polymer materials for the electrodes have a correspondence between battery voltage and battery capacity, so this can be utilized. By checking the battery voltage by checking the battery voltage, it is easy to determine the period of use up to the limit that can supply the memory retention voltage of the IC memory without any problem, and therefore the I
I that can stably supply the memory holding voltage of C memory
C memory backup can be configured compactly.

Here, it is preferable to use polyaniline as the conductive polymer material, which not only has a large battery capacity per electrode active material but also provides a secondary battery with excellent charge/discharge repeatability. It is possible to configure an IC memory backup equipped with a higher performance battery power source. Hereinafter, typical embodiments of the present invention will be described with reference to the drawings.

The following drawings show the basic electric circuit of an IC memory backup 1 according to an embodiment of the present invention. 4 and diode 5 (D)
, diode 6 (D2).

It is connected via diode 7 (D3).

Here, the system power supply 2 is introduced from a power supply for operating an electronic equipment system such as a personal computer, word processor, facsimile, etc., and is applied to the IC memory 4 within the system at a memory retention voltage, that is, a constant positive DC voltage ( It is a DC constant voltage power supply that is adjusted to be able to supply V s ) to the IC memory 4, and normally supplies the memory retention voltage to the IC memory 4 as required.
This is to ensure that the memory contents of the memory are retained without being erased. In addition, the system power supply 2 detects a power fail in the event of a power failure or other abnormality when a power fail occurs in the system, and transmits a power fail signal, and also responds to a drop in the system power supply voltage to the IC memory 4.
Some cases have a built-in mechanism to stop the voltage supply to.

Further, the battery power supply 3 is a DC constant voltage power supply that receives the power fail signal described above and operates when the voltage supply of the system voltage g2 is stopped, and supplies a memory retention voltage to the IC memory 4. It is connected to the IC memory 4 via a diode 6 so as to be able to supply a constant positive DC voltage (VB) of a predetermined magnitude or more to the IC memory 4 .

In this case, the power supply voltage VB of the battery power supply 3 varies depending on the type of IC used for the IC memory, and is not particularly limited.
In the case of RAM (TC5516AP/18BP), 3v to 4.5v is suitable.

The IC memory backup 1 supplies a memory retention voltage to the IC memory 4 when the power is cut off or other power failure occurs in the system by the battery power supply 3 using the above-mentioned secondary battery, and the voltage is transmitted from the system power supply 2. A mechanism that receives a power fail signal is preferable;
In this case, a volatile IC memory is used as the IC memory 4, and information is input as an electrical signal consisting of a bit arrangement pattern to a specified address via a decoder, temporarily stored, and used for calculations, data processing, etc. It is output at the appropriate time when processing the information, and cleared when it is not needed.In addition, in the event of an abnormality such as a power cut or other power failure in the system, the memory contents that store the switching between system power supply 2 and battery power supply 3 are output. The memory is placed on standby (datalization) using the aforementioned power fail signal so that operations can be performed without any damage or trouble.
A standby mode is included.

Note that a diode 5 (D,) is present between the system power supply 2 and the IC memory 4, a diode 6 (D2) is present between the battery power supply 3 and the IC memory, and a diode 6 (D2) is present between the battery power supply 3 and the system power supply 2. The diode 7 (D3) interposed in the IC memory 4 side prevents the inflow and outflow of reverse current and prevents power fail etc. when switching between the system power supply 2 and the battery power supply 3. The current is set to flow.

In the IC memory bank up 1 having the above configuration, the system power supply 2 supplies a memory holding voltage of approximately 2.0 V or more, which is normally required for the IC memory 4 to hold the memory contents, to hold the memory contents. However, in the event of an abnormality such as a power cut or other power fail in the system, the memory retention voltage is automatically supplied from the battery power supply 3 to the IC memory 4 at the above abnormality, and preferably in the system power supply 2. It detects a power fail, sends a power fail signal, puts the IC memory 4 in standby mode, stops voltage supply to the IC memory 4, and switches to the battery power source 3 while the IC memory 4 is in standby mode. .

Here, in the present invention, a secondary battery is used as the battery power source 3 in which the electrode active material of at least one of the negative electrode and the positive electrode is made of a conductive polymer material.

In this case, the conductive polymer material is not particularly limited as long as it can be used as an electrode active material of a battery.
For example, conductive inorganic polymer materials such as polythiazyl, carbon fiber, and graphite, polymers of benzene and its derivatives such as polyacetylene, polybenzene, polyparaphenylene, polyaniline, polytriphenylamine, polydibutoxyphenylene, polyphenylene vinylene, and polyquinoline, and polypyridine. , polythiophene, polyfuran, polypyrrole, and polymers of hetero or polynuclear aromatic compounds such as anthracene and naphthalene. Among them, polyaniline is made by adding aniline to platinum and carbon in an acidic solution.

By electrolytically oxidizing on an anode made of a substrate such as stainless steel or lead, or by chemically oxidizing with an oxidizing agent such as iron oxide in an acidic solution, both film and powder forms can be easily processed. It is suitable because it can be manufactured and obtained, has a low internal resistance, has an extremely high coulombic efficiency, and can therefore form a secondary battery with excellent durability against repeated charging and discharging. In particular, polyaniline obtained by electrolytic oxidation polymerization is deposited and formed into a film with good adhesion to the anode substrate during electrolytic oxidation polymerization, and the anode substrate can be used as a current collector for battery electrodes, making it suitable for the battery manufacturing process. It is more preferable to use this polyaniline as an electrode active material of a secondary battery because it can be simplified and the secondary battery can be made smaller and lighter. Due to the shape of the stainless steel substrate used as the anode, legally obtained polyaniline can be used as a current collector or container for secondary batteries, simplifying the battery manufacturing process and manufacturing secondary batteries at low cost. This is even more preferable from the viewpoint that it is possible to do so.

In this case, the polyaniline usually has an aniline concentration of 0.
01-5 mol/Ω, especially 0.5-3 mol/Q and acid concentration 0.02-10 mol/Q, especially 1-6 mol/Q
Particularly suitable are those obtained by electrolytic polymerization using an electrolytic solution containing. Note that the acid used in the electrolytic solution for the electrolytic polymerization is not particularly limited, but includes hydrofluoric acid, hydrochloric acid, and sulfuric acid.

Nitric acid, perchloric acid, fluoroboric acid, acetic acid and the like are preferred, among which hydrochloric acid, perchloric acid and fluoroboric acid are preferred. Further, the temperature of the electrolytic solution is preferably in the range of 0 to 30°C from the viewpoint of the production rate of polyaniline, and it is even more preferable to set the temperature to 20°C or less because the film forming property of polyaniline is improved.

When the above-mentioned conductive polymer materials including polyaniline are used as electrode active materials in at least one of the positive electrode and the negative electrode, the electrode reactions of charging and discharging generally occur according to a doping and doping mechanism. There is a correspondence between battery voltage and battery capacity. Therefore, by checking the battery voltage using this correspondence, the maximum usage period until the memory retention voltage of the IC memory 4 can be supplied without any problems can be determined. It has the advantage of being easy to judge.

Note that the conductive polymer material can be used as an electrode active material for the positive electrode, negative electrode, and both electrodes; From the point of view of constructing an electrochemical reaction system in which the reaction can be performed reversibly and the redox potential generated by the electrode reaction corresponding to the radioactive process is high, for example, the standard unipolar potential EA (25°C) -3,045
Utilizing the electrode reaction between V and high lithium, a conductive polymer material such as polyaniline is used for the positive electrode, lithium or a lithium alloy is used as the electrode active material for the negative electrode, and the electrolyte is a combination of lithium ions (Li'') and anions. A secondary battery using the following is suitable.

In this case, the lithium alloy used for the negative electrode active material is not particularly limited as long as it is an alloy of lithium and a metal that can be alloyed with it, such as lithium and aluminum, magnesium, indium, or mercury.

Examples include alloys with one or more of zinc, cadmium, etc., but as the negative electrode active material, lithium or an alloy of lithium with one of the metals aluminum, indium, and zinc among the above-mentioned lithium alloys is preferable. It is.

In addition, examples of anions constituting the electrolyte include P F
r,-,SbF,-,AsF6-. 5bCD, -, a halide anion of a group VA element such as B F, -.

Halide anions of group IIIA elements such as Al1C (14-), halogen anions such as I-(I,-), Br-, Cf1-, perchlorate anions such as cpo4-, HF2-.

CF, SO,-, SCN-, SOnie, Hs
Examples include o, -, etc., but the anion is not necessarily limited to these anions.

A specific example of an electrolyte consisting of such a combination of Li+ and anion is LiPF6. Li5bF,.

LiAsF6. LiCQO,,LiI,LiBr,Li
CQ.

LiBF4. LiAQCO4, LiHF, Li5CN
etc. Among these, especially LiCnO
4°LiBF4 is preferred.

Note that these electrolytes are usually used in a state dissolved in a solvent, and in this case, a relatively highly polar solvent is preferably used as the solvent. Specifically, propylene carbonate, ethylene carbonate, benzonitrile, acetonitrile, tetrahydrofuran, 2-methyltetrahydrofuran, γ-butyrolactone, triethyl phosphate, triethyl phosphite, dimethyl sulfate, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, dioxane. , dimethoxyethane, polyethylene glycol, sulfuran, dichloroethane, chlorobenzene, nitrobenzene, water, etc., or a mixture of two or more thereof. Among these,
Particularly suitable is a mixed solvent formed by mixing propylene carbonate with one or more solvents selected from 1-xyethane, tetrahydrofuran, and γ-butyrolactone.

The electrolyte constituting the secondary battery includes an organic solid electrolyte in which the electrolyte is impregnated with a polymer such as polyethylene oxide, polypropylene oxide, a crosslinked product of polyethylene oxide, a phosphazene polymer having an ethylene oxide oligomer in its side chain, Li, N.LiBC
Inorganic ionic conductors such as Q4, Li, SiO, Li5B
An inorganic solid electrolyte such as lithium glass such as ○3 can also be used.

A secondary battery is usually constructed by interposing an electrolyte between the positive and negative electrodes, but in this case, if necessary, a diaphragm such as a porous membrane made of synthetic resin such as polyethylene or natural fiber paper is inserted between the positive and negative electrodes. separator).

Note that the IC memory backup of the present invention is not limited to the above-mentioned embodiments, and can be applied to, for example, a personal computer, a word processor,
If the electronic device system used, such as a facsimile machine, has sufficient power and voltage, a battery supplementary power source and a diode are additionally attached, and the battery supplementary power source is connected to the battery power source via the diode, so that the battery supplementary power source can be switched on from the battery power source in a timely manner. Alternatively, the battery power supply may be equipped with a voltmeter and an alarm that issues an alarm when the voltage reaches a predetermined level or less to detect the timing of charging and replenishment of the battery power supply. Both may be attached together, and both may be linked so that the battery power source is automatically recharged when the battery power source is recharged, and various changes may be made within the scope of the gist of the invention. .

Next, we will show the effect of using a secondary battery using a conductive polymer material as an electrode active material in an uninvented IC memory backup as a battery power source.

〔Example〕

A coin-type proprietary polymer secondary battery was connected via a diode as a battery power source to an IC memory having an S RAM (memory capacity 64 Kbit) as a storage element.

The coin-type secondary battery used here had a positive electrode whose positive active material was polyaniline produced by the following method;
It is equipped with a negative electrode whose negative electrode active material is made of a lithium-aluminum alloy, an electrolyte made of propylene carbonate containing 1 mol/Q of LiBF4, and is configured in a coin shape with a thickness of 1.6 m++ and a diameter of 2.0 mouths. , its battery capacity is about 4mAh, and the operating voltage (battery voltage) is about 3.3~2
．． The range is 5v.

Further, the above polyaniline was produced by electrolytic polymerization on a 1.5 φ stainless steel mesh using an electrolytic solution consisting of an aqueous solution containing 1.5 mol/Q aniline and 3.0 mol/Q HBF. It was manufactured by depositing an amount equivalent to 50 mg.

As a battery power source, one coin-type conductive polymer secondary battery is enough to hold the IC memory, and the battery space is approximately 0.5A+? Met. I
A current of approximately 3 μA flows to the C memory side, and the battery voltage increases to 3. O
When switching to the system power supply at point V and holding the IC memory using the battery power, the memory holding time was approximately 1100 hours, and the battery capacity i3. om
This almost coincides with the memory retention time of 1000 hours estimated from Ah, and it was found that the timing of charging and replenishing the battery power source can be set.

[Hisame example]

Voltage 1 instead of the coin-shaped conductive polymer secondary battery in the example
．． In order to use a coin-type nickel-cadmium battery of 2V, thickness 2.0mm, and diameter 2.3cm as the battery power source for the IC memory backup similar to the embodiment and to retain the memory of the IC memory, the above coin-type nickel-cadmium battery is used. Three nickel-cadmium batteries were required to be arranged in series, thus requiring approximately 3.0 cd of battery space.

Using an IC memory backup similar to the above embodiment equipped with a battery power source, when switching to the system power source and holding the IC memory using the battery power source, the voltage remained at approximately 3.6 V even after several hours had passed since the power was turned off. However, it was impossible to set the timing of charging and discharging the battery power supply based on the voltage of the battery power supply.

As explained above, the IC memory backup of the present invention is a battery power source included in the IC memory backup, and the electrode active material of at least one of the negative electrode and the positive electrode is made of a conductive polymer material. Although it uses a secondary battery, it can output a high enough voltage to retain the memory contents of the IC memory as described above, and it can be constructed in a small size, so the battery power source is not required. It is possible to reduce the battery space and make the IC memory backup more compact.Also, since the battery voltage of the above-mentioned secondary battery changes according to the battery capacity, the battery power source using this battery can charge the battery power source from that voltage. This has the advantage that the timing of replenishment can be easily set.

[Brief explanation of drawings]

The drawing is an electric circuit diagram of an IC memory backup according to an embodiment of the present invention. 1...IC memory backup, 2...system power supply, 3...battery power supply, 4.
...IC memory.

Claims (1)

[Claims] 1. A system power supply and a battery power supply are provided, and when the system power supply voltage drops, the voltage supply from the system power supply is stopped in response to the drop in the system power supply voltage, and the battery power supply is stopped. An IC that retains the stored contents of an IC memory by operating and supplying voltage.
An IC memory backup, characterized in that the battery power source is a secondary battery in which the electrode active material of at least one of a negative electrode and a positive electrode is made of a conductive polymer material. 2. The IC memory backup according to claim 1, wherein the conductive polymer material is polyaniline.