MITSMI MM1245BF, MM1245CD, MM1245CF, MM1134BF, MM1026BF Datasheet
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MITSUMI
System Reset (with battery back-up) MM1026, 1245, 1080, 1134
System Reset (with battery back-up)
Monolithic IC MM1026, 1245, 1080 ,1134
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
Characteristics
1. Battery back-up
1. Low IC current consumption (loss current) 0.3µA typ.
2. Drop voltage inside IC (input/output voltage difference) I
O=100µA 0.3V typ.
3. Reverse current (reverse leak current) 0.1µA max.
2. Normal operation
1. Drop voltage inside IC (input/output voltage difference) I
O=50µA 0.2V typ.
2. Output voltage V
CC=5V IO=50mA 4.8V typ.
3. Battery-V
CC switching voltage 3.3V typ.
4. Detection voltage (CS, CS
---------------------------------------------------------
, reset output) A : 3.5V typ.
B : 4.2V typ.
C : 4.5V typ.
MITSUMI
System Reset (with battery back-up) MM1026, 1245, 1080, 1134
Package
DIP-8B (MM D)
SOP-8C (MM F)
*
contains detection voltage rank.
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
Pin no.
Pin name
MM1026 MM1245 MM1080 MM1134
1 GND GND GND GND
2
RESET
T
C NC
RESET
3 CS CS CS CS
4 V
BATT VBATT VBATT VBATT
5
CS CS
NC
CS
6 V
OUT VOUT VOUT VOUT
7 NC Tr.B NC Y
8 V
CC VCC VCC VCC
Pin Assignment
1432
8567
DIP-8P(C)/SOP-8P(C)/SOP-8P(C) Taping
Block Diagram
MM1026
MITSUMI
System Reset (with battery back-up) MM1026, 1245, 1080, 1134
MM1080
MM1134
MM1245
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