Conceptual
RT9293
VFB vs. Input Voltage
VFB vs. Temperature
0.32
0.29
0.26
0.34
0.33
0.32
0.31
0.30
0.29
0.28
0.27
0.26
VIN = 3V
VOUT = 34V, IOUT = No Load
VIN = 3.7V
VIN = 4.2V
10WLED, ILED = 20mA
0.23
0.2
ILED = 20mA
0.17
2.5
3
3.5
4
4.5
5
5.5
-40
-15
10
35
60
85
(°C)
Temperature
Input Voltage (V)
Enable Voltage vs. Input Voltage
VFB vs. Output Current
0.314
0.310
0.306
0.302
0.298
0.294
0.290
1.00
0.98
0.96
0.94
0.92
0.90
0.88
0.86
0.84
0.82
0.80
VIN = 3V
Rising
VIN = 4.2V
VIN = 3.7V
Falling
VOUT = 34V
25 30
0
5
10
15
20
2.5
3
3.5
4
4.5
5
5.5
Input Voltage (V)
Output Current (mA)
LED Current vs. Duty
Power On from EN
25
20
15
10
5
VEN
(2V/Div)
f = 200Hz
f = 2kHz
f = 20kHz
f = 200kHz
VOUT
(10V/Div)
VIN = 3.7V, ILED = 20mA
Time (1ms/Div)
VIN = 3.7V, ILED = 20mA
0
0
10 20 30 40 50 60 70 80 90 100
Duty (%)
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6
DS9293-03C April 2008
ETC [ ETC ]
