LED Driver PR4401 / PR4402

Typical Characteristics

TEST CIRCUIT

Vcc

Gnd

Vout

PR4401

L1

0.5

Ω

or 1

Ω

470 nF

0.5

Ω

or 1

Ω

MEASUREMENT + CALCULATION OF EFFICIENCY

Efficiency [%]=

1

0

T

1

0

T

⋅

100

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: ±1 mA.

Measuring conditions for all diagrams, unless

otherwise noted:

• Ta = 25°C

• one LED connected (peak voltage 4.2...5.8 V)

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)

• 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

Ω resistor)

with L1 = 22 µH

with L1 = 10 µH

© PREMA Semiconductor GmbH 2006-2014 I rev. 1014

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