ELM94xxB
CMOS PFM step-up DC/DC converter
■General description
ELM94xxB is CMOS step-up DC/DC converter which consists of reference voltage source, error amplifier,
oscillation circuit, start-up circuit, PFM control circuit, switching transistor and output voltage setting resistor.
For external parts, coil, diode and capacitor are possible choices; with external parts, ELM94 series is able to
acquire constant output voltage higher than input voltage. The standard output voltages are 2.7V, 3.0V, 3.3V, and
5.0V; ELM94 series can also be designed as semi-custom IC within the range of 2.5V to 5.5V by 0.1V step.
■Features
•
•
•
•
•
•
•
Output voltage range
Low voltage operation
Low power operation
High efficiency
High output voltage accuracy
Output current(e.g.)
Package
: 2.5V to 5.5V (by 0.1V)
: Vin≥0.98V (RL=30kΩ)
: 12μW (Typ. ELM9430B)
: Typ. 80%
: ±2.5%
: 20mA (When Vin=1.5V, Vout=3.0V)
: SOT-89
■Application
• Constant voltage source for battery-
operated devices
• Constant voltage source for cameras
• Portable communication equipments
• Local regulator
■Maximum absolute ratings
Parameter
Apply voltage to LX pin
Apply voltage to VOUT pin
Output current of LX pin
Power dissipation
Operating temperature
Storage temperature
Symbol
Vlx
Vout
Ilx
Pd
Top
Tstg
Limit
12
12
200
300
-40 to +85
-55 to +125
Unit
V
V
mA
mW
°C
°C
■Selection guide
ELM94xxB-x
Symbol
a, b
c
d
Output voltage
Product version
Taping direction
e.g. :
27: Vout=2.7V 30: Vout=3.0V
33: Vout=3.3V 50: Vout=5.0V
B
S : Refer to PKG file
N : Refer to PKG file
ELM94 x x B - x
↑ ↑ ↑ ↑
a b c d
■Pin configuration
SOT-89 (TOP VIEW)
Pin No.
1
2
3
Pin name
VSS
VOUT
LX
6-1