ILD4001 Infineon Technologies, ILD4001 Datasheet - Page 15

• Manufacturer Part Number: ILD4001
• Manufacturer: Infineon Technologies
• Type: Buckr

Specifications of ILD4001

• Packages: SC74
• Vs (min): 4.5 V
• Vs (max): 42.0 V
• Iout (typ): 10.0 mA
• Iout (max): -

6
This section covers the basic information required for calculating the parameters for a certain LED application.
For detailed application information please check the application note AN213 (Driving 2 - 5 W LEDs with ILD4001)
or visit our web site http://www.infineon.com/lowcostleddrivers
6.1
An external MOSFET is required to drive the LEDs in the ILD4001 application. There are a few factors to be
considered while choosing the suitable external MOSFET. First, choose the correct voltage and current rating of
the MOSFET. Please ensure the
external MOSFET is working within the safe operating area region of DC mode. Second, the logic high level from
ILD4001 is 5 V and the external MOSFET must be able to be driven with a 5 V gate voltage. Third, choose a low
R
The BSR302N is recommended for supply voltages up to 30 V and an output current up to 3.7 A. For higher supply
voltages up to 42 V, the BSP318S is recommended with an output current of up to 2.6 A.
For an overview of all suitable MOSFETs please visit
6.2
The average output current for the LEDs is set by the external sense resistor
resistor a first approximation can be calculated using
V
Example Calculation
V
For this configuration
→
An easy way to achieve this resistor value is to connect several standard resistors in parallel.
Data Sheet
R
DSON
sense
s
sense
= 12 V,
R
sense
is dependent on the supply voltage
=
MOSFET to improve the efficiency of the system.
V
I
= 158 mΩ according to
sense
LED
I
LED
Basic Application Information
External MOSFET
Setting the Average LED Current
= 730 mA, L = 68 µH,
V
sense
will settle at 116 mV.
Equation (2)
V
DS
breakdown voltage and
V
fLED
V
s
= 3 V, 3 LEDs in series
and the number of LEDs in series.
Step down LED Controller for high power LEDs
Equation
http://www.infineon.com/smallsignalmosfets
15
I
DS
(2).
current capability is sufficient and ensure that the
R
sense
Basic Application Information
. To calculate the value of this
Revision 2.0, 2011-06-09
ILD4001
(2)