Datasheet
V
ADJ
(V)
I
LED
(A)
2.3
1.8
1.4
0.9
0.5
0.0
0.0 0.3 0.5 0.8 1.0 1.3
INPUT VOLTAGE (V)
NORMALIZED SWITCHING FREQUENCY
1.7
1.4
1.0
0.7
0.3
0.0
0 14 28 42 56 70
7 LEDs
5 LEDs
3 LEDs
1 LED
INPUT VOLTAGE (V)
I
LED
(A)
2.40
2.35
2.30
2.25
2.20
2.15
2.10
20 24 28 32 36 40 44
INPUT VOLTAGE (V)
I
LED
(A)
2.5
2.4
2.3
2.2
2.1
2.0
20 32 44 56 68 80
INPUT VOLTAGE (V)
EFFICIENCY (%)
100
95
90
85
80
75
70
0 10 20 30 40 50
INPUT VOLTAGE (V)
EFFICIENCY (%)
100
95
90
85
80
75
70
0 20 40 60 80
300856b3
LM3409, LM3409HV, LM3409-Q1
SNVS602J –MARCH 2009–REVISED MAY 2013
www.ti.com
Typical Performance Characteristics (continued)
T
A
= +25°C, V
IN
= 24V, and characteristics are identical for LM3409 and LM3409HV unless otherwise specified.
LM3409 Efficiency vs. Input Voltage LM3409HV Efficiency vs. Input Voltage
V
O
= 10V (3 LEDs); I
LED
= 2A
(1)
V
O
= 10V (3 LEDs); I
LED
= 2A
(2)
Figure 9. Figure 10.
LM3409 LED Current vs. Input Voltage LM3409HV LED Current vs. Input Voltage
V
O
= 17V (5 LEDs)
(3)
V
O
= 17V (5 LEDs)
(4)
Figure 11. Figure 12.
Amplitude Dimming Using IADJ Pin
Normalized Switching Frequency vs. Input Voltage V
O
= 17V (5 LEDs); V
IN
= 24V
Figure 13. Figure 14.
(1) The measurements were made using the Bill of Materials from Design #3 except the LM3409 was substituted for the LM3409HV.
(2) The measurements were made using the Bill of Materials from Design #3.
(3) The measurements were made using the Bill of Materials from Design #3 except the LM3409 was substituted for the LM3409HV.
(4) The measurements were made using the Bill of Materials from Design #3.
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