MITSUMI
Step-Up DC/DC Converter (PWM) MM1349
Step-Up DC/DC Converter (PWM)
Monolithic IC MM1349
Outline
This is a converter IC which steps up the DC input voltage to output a fixed voltage level. Utilizing technology
for low-voltage operation, which is a feature of Mitsumi semiconductor processes, operation is possible
beginning at 0.90V, making this device ideal for the power supply circuits of portable equipment driven by a
single battery.
Because PWM oscillation is adopted, an output waveform can be obtained with a smaller peak-to-peak
voltage than is possible for VFM devices.
Features
1. Low-voltage operation possible, 0.90V (no-load)
2. Internal oscillation circuit
3. Adoption of PWM oscillation for output waveform with small peak-to-peak voltage
4. Numerous output voltages available (seven ranks)
Package
SOT-25
Pin Assignment
1
3
5
2
4
SOT-25
Applications
1. Pagers
2. Separate vibrators
3. Other portable equipment
Output Voltage Rank
Rank
A
B
C
D
E
G
H
Voltage (V)
5.0
3.5
3.2
3.0
2.7
2.5
2.2
1
GND
2
SUB
3
V
L
4
V
OUT
5
V
IN
*
Pin 2 is the SUB pin, and should be connected to GND.
MITSUMI
Step-Up DC/DC Converter (PWM) MM1349
Block Diagram
Note: Pin 2 is the SUB pin, and should be connected to GND.
Absolute Maximum Ratings
(Ta=25C)
Item
Symbol
Ratings
Units
Storage temperature
T
STG
-40~+125
C
Operating temperature
T
OPR
-20~+75
C
Voltage applied to V
IN
pin
-0.3~+10.0
V
Voltage applied to V
OUT
pin
-0.3~+10.0
V
Voltage applied to V
L
pin
-0.3~+10.0
V
Allowable loss
Pd
150
mW
Recommended Operating Conditions
Item
Symbol
Ratings
Units
Operating temperature
Top
-20~+75
C
Operating voltage
Vop
+0.9~V
OUT
V
MITSUMI
Step-Up DC/DC Converter (PWM) MM1349
Electrical Characteristics
(Ta=25C)(Except where noted otherwise,V
IN
=1.5V, I
O
=1mA)
Item
Symbol
Measurement conditions
Min. Typ. Max. Units
Operating voltage
V
IN
No-load
0.90
V
OUT
V
A
4.80
5.00
5.20
B
3.36
3.50
3.64
C
3.07
3.20
3.33
Output voltage
V
OUT
V
IN
=1.5V, Io=1mA
D
2.88
3.00
3.12
V
E
2.59
2.70
2.81
F
2.40
2.50
2.60
G
2.11
2.20
2.29
Output voltage temperature coefficient
Ta=-20~75C
100
ppm/C
Input fluctuations
V
IN
=1.1 1.7V, Io=1mA
1
%/V
Load fluctuation
V
IN
=1.5V, Io=0 4mA
1
%/mA
Efficiency
V
IN
=1.5V, Io=1mA
80
A
V
L
pin leakage current
I
VLLK
V
L
=10V
1
A
Oscillation frequency
f
OSC
V
IN
=1.5V, Io=1mA
35
65
95
kHz
Note: These characteristics assume the following externally mounted components.
Coil: L=120H (Mitsumi model C5-R)
Capacitor: C=33F (tantalum electrolytic capacitor)
Schottky barrier diode (Rohm model RB451F)
Measuring Circuit
Note 1: A: DC ammeter
V: DC voltmeter
Note 2: L=120H
Application Circuits
Coil: L=120H (Mitsumi model C5-R)
Capacitor: C=33F (tantalum electrolytic capacitor)
Schottky barrier diode (Rohm model RB451F)
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