LED DRIVER PR4401/PR4402

0.9V Boost Driver for White LEDs PR4401/4402

Requires Only One External Component

The PR4401 and PR4402* are single cell step-up converters for white LEDs operating

from a supply voltage of less than 0.9V. Only one external inductor is needed for operation

of a white LED. PR4401 is recommended for mean LED currents of up to 20mA, PR4402

for up to 40mA. This makes PR4401 and PR4402 ideal for use in low-cost or small-sized

applications such as LED flashlights or LCD backlighting for portable devices.

Features

Applications

• minimum startup voltage 0.9V

• Small-sized LED torches

• 200/250mA peak output current

• LCD backlighting

• only one external component required

• LED indicator lights

• battery deep discharge protection

Typical Application

Vcc

Gnd

Vout

PR4401/02

Vbat =1.2V or 1.5V

L1

White

LED

For output currents higher than 20mA an additional

blocking capacitor at Vcc is recommended.

The inductance L1 determines the LED

current:

Inductance L1

Mean current

for

47µH

6.5 mA

PR4401

32µH

8.3 mA

PR4401

26.7µH

10.8 mA

PR4401

22 µH

11 mA

PR4401

14.7 µH

14 mA

PR4401

10 µH

22 mA

PR4401/4402

6.8 µH *

32 mA *

PR4402

4.7 µH *

40 mA *

PR4402

* PR4402 only measured with inductor Murata type

LQH32C series

10-22µH: one white LED

4.7-6.8µH: two white LEDs in parallel

Pin Description

PIN Name

PIN Function Description

Vcc

Supply voltage

Vout

Output voltage, LED connection

Gnd

Ground connection

Topside marking: "UI" (PR4401) or "UJ" (PR4402) with a two-digit lot code

Package SOT23-3 or COB on request

© PREMA Semiconductor GmbH 2006-2008

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Rev 0908

Vcc

Vout

Gnd

top view