Datasheet
I
LED
(A)
V
EN
(V)
7
6
5
4
3
2
1
0
-1
2.8
2.4
2.0
1.6
1.2
0.8
0.4
0.0
-0.4
I
LED
2 és/DIV
3.5 és
V
EN
I
LED
(A)
V
PWM2
(V)
7
6
5
4
3
2
1
0
-1
2.8
2.4
2.0
1.6
1.2
0.8
0.4
0.0
-0.4
I
LED
200 ns/DIV
V
PWM2
I
LED
(A)
V
EN
(V)
14
12
10
8
6
4
2
0
-2
2.0
1.5
1.0
0.5
0.0
-0.5
-1.0
-1.5
-2.0
I
LED
10 és/DIV
V
EN
I
LED
(A)
V
PWM2
(V)
14
12
10
8
6
4
2
0
-2
2.0
1.5
1.0
0.5
0.0
-0.5
-1.0
-1.5
-2.0
I
LED
2 és/DIV
V
PWM2
DUTY CYCLE (%)
I
LED
(A)
2.3
1.8
1.4
0.9
0.5
0.0
0 20 40 60 80 100
1kHz
20kHz
DUTY CYCLE (%)
I
LED
(A)
2.3
1.8
1.4
0.9
0.5
0.0
0 20 40 60 80 100
50 kHz
100 kHz
LM3409, LM3409HV, LM3409-Q1
www.ti.com
SNVS602J –MARCH 2009–REVISED MAY 2013
Typical Performance Characteristics (continued)
T
A
= +25°C, V
IN
= 24V, and characteristics are identical for LM3409 and LM3409HV unless otherwise specified.
Internal EN Pin PWM Dimming External Parallel FET PWM Dimming
V
O
= 17V (5 LEDs); V
IN
= 24V V
O
= 17V (5 LEDs); V
IN
= 24V
Figure 15. Figure 16.
20kHz 50% EN pin PWM dimming 100kHz 50% External FET PWM dimming
V
O
= 42V (12 LEDs); V
IN
= 48V
(5)
V
O
= 42V (12 LEDs); V
IN
= 48V
(5)
Figure 17. Figure 18.
20kHz 50% EN pin PWM dimming (rising edge) 100kHz 50% External FET PWM dimming (rising edge)
V
O
= 42V (12 LEDs); V
IN
= 48V
(6)
V
O
= 42V (12 LEDs); V
IN
= 48V
(6)
Figure 19. Figure 20.
(5) The waveforms were acquired using the standard evaluation board from AN-1953 (SNVA390).
(6) The waveforms were acquired using the standard evaluation board from AN-1953 (SNVA390).
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