ILD4001 Infineon Technologies, ILD4001 Datasheet - Page 18

• 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): -

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.
Figure 6
During the low state of the PWM signal ILD4001 doesn’t pull low the
driven and intended gate discharge time (about 1 µs is recommended) a 10 - 100 kΩ shunt resistor to GND is
required to avoid a floating gate of the MOSFET.
6.4
For all shown switching parameters ILD4001 has been measured on evaluation board ILD4035/4001 using a
BSP318S N-channel MOSFET at
for further details.
Data Sheet
Figure 6
PWM Dimming: 3 dB Deviation of Contrast Ratio to Linear Dimming (12 V, 68 µH, 3 LEDs)
Switching Parameters
1000
100
10
1
100
based on the measured average LED current deviating 3 dB from the linear reference. The
T
A
= 25 °C. Used LEDs have a typical
PWM Dimming Frequency [Hz]
Step down LED Controller for high power LEDs
18
1000
V
drive
V
fLED
signal. Depending on gate capacitance
of 3 V. See application note AN213
Basic Application Information
Revision 2.0, 2011-06-09
10000
ILD4001