CMOS PFM step-up DC/DC converter
ELM94xxB
■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
■Application
• Output voltage range
• Low voltage operation
• Low power operation
• High efficiency
: 2.5V to 5.5V (by 0.1V)
: Vin≥0.98V (RL=30kΩ)
: 12μW (Typ. ELM9430B)
: Typ. 80%
• Constant voltage source for battery-
operated devices
• Constant voltage source for cameras
• Portable communication equipments
• Local regulator
• High output voltage accuracy : 2.5%
• Output current(e.g.)
• Package
: 20mA (When Vin=1.5V, Vout=3.0V)
: SOT-89
■Maximum absolute ratings
Parameter
Apply voltage to LX pin
Apply voltage to VOUT pin
Output current of LX pin
Power dissipation
Symbol
Vlx
Vout
Ilx
Pd
Top
Limit
12
12
200
300
-40 to +85
-55 to +125
Unit
V
V
mA
mW
°C
Operating temperature
Storage temperature
Tstg
°C
■Selection guide
ELM94xxB-x
Symbol
e.g. :
a, b
Output voltage
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
c
Product version
Taping direction
d
d
■Pin configuration
SOT-89 (TOP VIEW)
Pin No.
Pin name
VSS
VOUT
LX
1
2
3
6 - 1
ELM-TECH [ ELM Technology Corporation ]
