MITSUMI
High-Precision Three-Pin Regulator MM1257
High-Precision Three-Pin Regulator
Monolithic IC MM1257
Outline
This IC is a high-precision high-voltage stabilized power supply device which stands out from ordinary low-
saturation three-pin regulators.
It can be used at a wide range of output voltages, from 3V to 12V, delivering output currents up to 100mA. It
is one of a series of devices available at lower prices than previous regulators.
Features
1. Input current
27V max.
2. Output noise voltage
200V
RMS
typ.
3. Maximum output current
100mA max.
4. No-load input current
500A typ.
5. Thermal shutdown circuit provided
6. Output voltage ranks
A : 12V2% E : 6V2%
B : 10V2% F : 5V2%
C : 9V2%
G : 3V2%
D : 8V2%
Package
TO-92A (MM1257 T)
MMP-4A (MM1257 M)
*
The output voltage rank appears in the boxes.
Applications
1. Handheld computers
2. Portable transceivers
3. Cordless phones
1
2
4
3
MMP-4A
1
2
3
TO-92A
Pin Assignment
1
NC
2
V
IN
3
V
OUT
4
GND
1
V
OUT
2
GND
3
V
IN
MITSUMI
High-Precision Three-Pin Regulator MM1257
Absolute Maximum Ratings
(Ta=25C)
Item
Symbol
Ratings
Units
Storage temperature
T
STG
-40~+125 C
Operating temperature
T
OPR
-20~+75
C
Power supply current
V
CC
max.
27
V
Output current
I
OUT
100 mA
Maximum Ratings
Pd
200 (MMP-4A), 300 (TO-92A)
mW
Recommended Operating Conditions
Item
Symbol
Ratings
Units
Input voltage
V
IN
7~27
V
Output current
I
O
1~100
mA
Pin Description
Pin no.
Pin name
Function
1
N.C
N.C
2
V
IN
Power supply input pin
3
V
OUT
Regulator output pin
4
GND
GND
Equivalent Circuit Diagram
PDF 
ZIP