ILD4035 Infineon Technologies, ILD4035 Datasheet - Page 17

• Manufacturer Part Number: ILD4035
• Manufacturer: Infineon Technologies
• Type: Buckr

Specifications of ILD4035

• Packages: SC74
• Vs (min): 4.5 V
• Vs (max): 40.0 V
• Iout (typ): 350.0 mA
• Iout (max): 400.0 mA

I
I
PWM Dimming
Besides the analog dimming functionality the EN/PWM pin acts as input for a pulse width modulated (PWM) signal
to control the dimming of the LED string. For PWM dimming the signal's logic high level should be at least 2.5 V
and the PWM frequency should be lower than 5 kHz. For the ILD4035/4001 demo board a dimming frequency less
than 330 Hz is recommended to maintain a maximum contrast ratio of 100:1. The achieveable contrast ratio is
shown on
maximum contrast ratio depends mainly on the rise time of the inductor current and is thus dependent on supply
voltage, inductor size and LED string forward voltage.
LED
LED
Data Sheet
versus
versus
0.4
0.3
0.2
0.1
0.35
0.25
0.15
0.05
0.4
0.3
0.2
0.1
0
0
1
1
Figure 4
1200 mΩ, 220 μH
105 °C
-40 °C
303 mΩ, 100 μH
333 mΩ, 100 μH
600 mΩ, 100 μH
25 °C
85 °C
V
V
EN
EN
,
, 333 mΩ, 100 µH
T
1.5
A
1.5
based on the measured average LED current deviating 3 dB from the linear reference. The
=25 °C
V
V
EN
EN
2
2
[V]
[V]
2.5
2.5
3
3
17
I
LED
110
100
90
80
70
60
50
40
30
20
10
(relative) versus
0
1
1200 mΩ, 220 μH
303 mΩ, 100 μH
333 mΩ, 100 μH
600 mΩ, 100 μH
350 mA Step Down LED Driver
1.5
V
Basic Application Information
EN
,
V
T
EN
A
2
Revision 2.0, 2011-08-17
=25 °C
[V]
2.5
ILD4035
3