MITSUMI
System Reset (with battery back-up) MM1025, 1174
System Reset (with battery back-up)
Monolithic IC MM1025, 1174
Outline
These ICs were developed for D-RAM and dummy S-RAM battery back-up. D-RAM and dummy S-RAM
power supplies differ from that of S-RAMs because 5V or 3.3V of power supply is required even during
battery back-up. Therefore, these ICs provide voltage from a stable power supply during both normal
operation and back-up. Also, the internal stable power supply switches automatically to battery back-up if the
main power supply voltage goes down for any reason.
Features
1. Battery back-up
MM1025
Current consumption 600µA typ.
Input/output voltage difference I
Output current 40mA max.
MM1174
Current consumption 300µA typ.
Input/output voltage difference I
Output current 40mA max.
2. Normal operation
MM1025
Input/output voltage difference I
Output current V
External transistor drive current V
Current consumption 900µA max.
MM1174 (for external transistor)
Input/output voltage difference I
Output current Depends on external transistor
External transistor drive current (no built-in TR) V
Current consumption 500µA max.
L=40mA 0.25V typ.
L=40mA 0.13V typ.
L=80mA (built-in transistor) 0.29V typ.
CC=6V 80mA typ.
CC= 6V 15mA typ.
L=200mA 0.13V typ.
CC=3.6V 10mA typ.
3. Switching voltage from V
MM1025 4.9V typ.
MM1174 3.25V typ.
4. V
CC-Battery forced switching and detection voltage adjustment possible
CC to Battery VCC=High Low
Package
SOP-8A
Applications
1. Memory cards (D-RAM cards, other)
2. PCs, word processors and other equipment with D-RAMs
3. Fax machines, photocopiers and other office equipment with D-RAMs
MITSUMI
Pin Assignment
System Reset (with battery back-up) MM1025, 1174
1
2 GND
3 GND
4 CS
Pin Description
Pin No. Pin name Function
1 Forced switching and detection voltage adjustment
2 GND
3 GND
4 CS
5 V
6 VOUT
7 VCC
8 TRB External transistor drive
Block Diagram
BATT
5 V
BATT
6 VOUT
7 VCC
8 TRB
Absolute Maximum Ratings
Item Symbol Rating Units
Operating temperature T
Storage temperature T
Maximum output current 1 I
Maximum output current 2 I
Power supply voltage V
Power consumption Pd 300 mW
(Ta=25°C)
OPR
STG 40~+125
L max. 80 mA
L max. 40 mA
CC
-
20~+70
-
0.3~+18 V
°
C
°
C