PR4401 Datasheet, PDF (3/12 Pages) List of Unclassifed Manufacturers – 0.9V Boost Driver for White LEDs PR4401/4402 Requires Only One External Component

LED DRIVER PR4401/PR4402
Typical Characteristics
Test circuit
0.5Ω
or 1Ω
L1
Vcc
470nF
Vout
Gnd
PR4401
0.5Ω
or 1Ω
Measurement and Calculation of Efficiency
∫∫ _{Efficiency %=}
1
T
T
0
1
T
  ^V _LED^⋅I _LED ^dt
T
⋅100
V _in⋅I _in  dt
0
Depending on test setup and measuring method, efficiency values can vary by approx. ±5%, and peak
current values can vary by up to ±20%, Accuracy of mean currents: ±1mA.
Measuring conditions for all diagrams, unless otherwise noted:
● Ta = 25°C
● one LED connected (peak voltage 4.2...5.8V)
A LQH32C from Murata has been used as reference inductor, the DC resistance is specified as 0.44 Ω ±
30% for 10 µH (max current 300 mA), 0.71 Ω ± 30% for 22 µH (max. current 250 mA) and 1.30 Ω ± 30% for a
47 µH inductor (max. current 170 mA).
Oscilloscope Displays
PR4401; LED voltage (CH1) and LED current (CH2, over 0.5 Ohm resistor)
with L1 = 22 µH
L1 = 10 µH
© PREMA Semiconductor GmbH 2006-2008
Page 3/12
Rev 0908