PR4401 Datasheet, PDF (1/12 Pages) List of Unclassifed Manufacturers – 0.9V Boost Driver for White LEDs PR4401/4402 Requires Only One External Component

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
• minimum startup voltage 0.9V
• 200/250mA peak output current
• only one external component required
• battery deep discharge protection
Applications
• Small-sized LED torches
• LCD backlighting
• LED indicator lights
Typical Application
Vbat =1.2V or 1.5V
L1
The inductance L1 determines the LED
current:
Inductance L1 Mean current
for
Vcc
47µH
6.5 mA
PR4401
Vout
Gnd
PR4401/02
White
LED
32µH
26.7µH
22 µH
14.7 µH
8.3 mA
10.8 mA
11 mA
14 mA
PR4401
PR4401
PR4401
PR4401
For output currents higher than 20mA an additional
blocking capacitor at Vcc is recommended.
10 µH
6.8 µH *
22 mA
32 mA *
PR4401/4402
PR4402
Pin Description
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
Vcc
Gnd
PIN Name
Vcc
Vout
Gnd
PIN Function Description
Supply voltage
Output voltage, LED connection
Ground connection
Vout
top view
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
Page 1/12
Rev 0908