Datasheet

60
65
70
75
80
85
90
95
100
0 5 10 15 20 25 30 35
INPUT VOLTAGE (V)
EFFICIENCY
(%)
1 series (700 mA)
2 series (700 mA)
1 series (1A)
12Vin
1:1
10:1
100:1
1000:1
10k:1
0.1 1
10
DIMMING FREQUENCY (kHz)
MAXIMUM CONTRAST RATIO
24Vin
60
65
70
75
80
85
90
95
100
0 5 10 15 20 25 30 35
INPUT VOLTAGE (V)
EFFICIENCY (%)
1 series
2 series
3 series
4 Ps/DIV
VIN
5V/DIV
VCS
10V/DIV
ILED
100 mA/DIV
0
100
200
300
400
500
600
700
800
0 5 10 15 20 25 30 35
INPUT VOLTAGE (V)
SWITCHING FREQUENCY
(
kHz
)
1 LED
2 Series LEDs
ILED
100 mA/DIV
2 Ps/DIV
VCS
20V/DIV
VDIM
2V/DIV
Typical Performance Characteristics www.ti.com
Figure 5. Switching Frequency vs VIN Figure 6. Dimming Waveforms
Figure 7. Startup Waveforms Figure 8. Efficiency vs Input Voltage
Driving 350 mA LEDs
Figure 9. Efficiency vs Input Voltage Figure 10. Maximum Contrast Ratio vs Dimming
Driving 700 mA and 1A LEDs Frequency (100:1 = 1% duty)
6
AN-1657 LM3401 Demo Board SNVA254C–August 2007–Revised April 2013
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