MITSUMI
System Reset (with battery back-up) MM1026, 1245, 1080, 1134
System Reset (with battery back-up)
Monolithic IC MM1026, 1245, 1080 ,1134
Outline
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These ICs protect S-RAM data in back-up mode (CS signal makes R-SAM CE pin low and C E 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)
2. Drop voltage inside IC (input/output voltage difference)
3. Reverse current (reverse leak current)
2. Normal operation
1. Drop voltage inside IC (input/output voltage difference)
2. Output voltage
V
CC
=5V
3. Battery-V
CC
switching voltage
, reset output)
4. Detection voltage (CS,
C
S
---------------------------------------------------------
I
O
=100µA
0.3µA typ.
0.3V typ.
0.1µA max.
0.2V typ.
4.8V typ.
3.3V typ.
I
O
=50µA
I
O
=50mA
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.
2.
3.
4.
5.
Memory cards (S-RAM cards)
PCs, word processors
Fax machines, photocopiers, other office equipment
Sequence controllers, other FA equipment
Video games and other equipment with S-RAMs
Pin Assignment
Pin no.
8
7
6
5
1
2
3
4
5
6
7
8
MM1026
GND
RESET
CS
V
BATT
CS
V
OUT
NC
V
CC
Pin name
MM1245
MM1080
GND
GND
NC
T
C
CS
CS
V
BATT
V
BATT
NC
CS
V
OUT
V
OUT
Tr.B
NC
V
CC
V
CC
MM1134
GND
RESET
CS
V
BATT
CS
V
OUT
Y
V
CC
1
2
3
4
DIP-8P(C)/SOP-8P(C)/SOP-8P(C) Taping
(TOP VIEW)
Block Diagram
MM1026
京公网安备 11010802033920号
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