Outline

These ICs were developed for STATIC-RAM (S-RAM) battery back-up, and have built-in switching circuit for main power supply and battery, back-up timing circuit and battery checker.

Features

1. Battery back-up

1. Low IC current consumption (loss current) 0.3μA typ.

2. Drop voltage inside IC (input/output voltage difference) IO=10μA 0.2V typ.

3. Reverse current (reverse leak current) 0.1μA max.

2. Normal operation

MM1027

Drop voltage inside IC (input/output voltage difference) IO=70mA 0.2V typ.

Output voltage VCC=5V IO=10mA 4.8V typ.

Current consumption D.CONT OPEN 3.0mA max.

External transistor drive current 25mA typ.

MM1081

Drop voltage inside IC (input/output voltage difference) IO=120mA 0.25V typ.

Output voltage VCC=5V IO=120mA 4.75V typ.

Current consumption 350μA max.

External transistor drive current (for output current increase) 25mA typ.

TC source current 3.0μA typ.

3. Battery-Vcc switching voltage 3.3V typ.

4. Detection voltage (CS, CS ------------------------------------------------) variable 4.2V typ.

5. Battery checker 1 X type 2.70V typ.

N type 2.50V typ.

6. Battery checker 2 X type 2.55V typ.

N type 2.35V typ.

Applications

1. IC memory cards (RAM cards)

2. PCs, word processors

3. Fax machines, photocopiers, other office equipment

4. Other equipment with S-RAMs (equipment requiring back-up)