1

http://www.elm-tech.com

Rev.1.2

22 -

■General description

Parameter

Symbol

Limit

Unit

Apply voltage to LX pin

Vlx

Vss-0.3 to 7.0

V

Apply voltage to VOUT pin

Vout

Vss-0.3 to 7.0

V

Output current of LX pin

Ilx

500

mA

Output current of EXT pin

Iext

20

mA

Power dissipation

Pd

500 (SOT-89)

mW

250 (SOT-23)

150 (SC-70-5)(SOT-353)

Operationg temperature

Top

-40 to +85

°C

Storage temperature

Tstg

-55 to +125

°C

• Output voltage range : 1.8V to 5.5V (by 0.1V)

• Low voltage operation : 0.9V(ELM91xx1xA: Iout=1mA)

• Oscillating frequency : Typ.100kHz

• Low power operation : Typ.40µW(ELM91301xA: Typ.100kHz)

• High efficiency

: 85%(ELM9130xxA: Vin=1.5V, Iout=10mA)

• Output current(e.g.)

: 100mA(Vin=1.5V, Vout=3.0V)

• Package

: SOT-89, SOT-23, SC-70-5(SOT-353)

• Constant voltage source for battery-

operated devices

• Portable communication equipments

and video recorders

ELM91xxxxA-x

Symbol

a, b

Output voltage

e.g. :

18: Vout=1.8V 30: Vout=3.0V

33: Vout=3.3V 50: Vout=5.0V

c

Switching transistor 1: Internal switch

3: External switch

d

Package

A: SOT-89

B: SOT-23

C: SC-70-5(SOT-353)

e

Product version

A

f

Taping direction

S , N: Refer to PKG file

ELM91 x x x x A - x

↑ ↑ ↑ ↑ ↑ ↑

a b c d e f

■Features

■Maximum absolute ratings

■Selection guide

■Application

ELM91xx1xA is CMOS PFM control step-up DC-DC converter; ELM91xx3xA is CMOS PFM control step-

up DC-DC controller, which has large output current capacity by using an external FET switch. ELM91 series

consists of reference voltage source, error amplifier, oscillation circuit, start-up circuit, PFM-control circuit,

switching current limit circuit (ELM91xx1xA only), switching transistor (ELM91xx1xA only) and output

voltage setting resistor. For external parts, coil, diode, MOSFET and capacitor are possible choices. The

standard output voltages are 1.8V,3.0V,3.3V,5.0V; ELM91 series can also be designed as semi-custom IC within

the range of 1.8V to 5.5V by 0.1V step.