Outline
These ICs protect S-RAM data in back-up mode (CS signal makes R-SAM CE pin low and CE pin high) when power supply voltage goes below a certain set voltage (detection voltage 3.5V, 4.2V or 4.5V typ.). Further, it switches from main power supply to battery back-up when power supply voltage drops. Conversely, when power supply rises, it first switches the S-RAM from battery back-up to main power supply (switching voltage 3.3V typ.), then from back-up mode to normal mode (CS signal makes S-RAM CE pin high and CE pin low).
These signal processes provide reliable protection against data damage.

Features
MM1026
• Power supply switching circuit (switching between main power supply and battery)
• CS control for S-RAM (normal mode : S-RAM can be accessed; back-up mode: S-RAM can not be accessed low current consumption mode)
• Reset output
MM1245
• Power supply switching circuit
• CS control for S-RAM
• CS control signal delay, power supply line chattering removal approx. 1S max.
• Supply current from main power supply can be increased by external power transistor
MM1080
• Power supply switching circuit
• CS control for S-RAM
• Low current consumption 60µA typ.
MM1134
• Power supply switching circuit
• CS control for S-RAM
• Gate circuit with CS signal

Applications
1. Memory cards (S-RAM cards)
2. PCs, word processors
3. Fax machines, photocopiers, other office equipment
4. Sequence controllers, other FA equipment
5. Video games and other equipment with S-RAMs