CAT37 Datasheet, PDF (4/11 Pages) Catalyst Semiconductor – CMOS White LED Driver Boost Converter

CAT37
TYPICAL CHARACTERISTICS
(V_IN = 3.6 V, T_AMB = 25°C, C_IN = 4.7 mF, C_OUT = 1 mF, L = 6.8 mH, unless otherwise specified.)
30
16.0
3 LEDs
20 mA
15.5
20
4 LEDs
15.0
10 mA
10
14.5
0
2
3
4
5
6
INPUT VOLTAGE (V)
Figure 2. LED Current vs. Input Voltage
14.0
−50 −25
0
25
50
75 100
TEMPERATURE (°C)
Figure 3. LED Current vs. Temperature
110
105
100
3 LEDs
95
90
85
80
0
5
10
15
20
LED CURRENT (mA)
Figure 4. FB Pin Voltage vs. LED Current
100
95
90
85
4 LEDs at 15 mA
VIN = 3.6 V
80
−50 −25
0
25
50
75 100
TEMPERATURE (°C)
Figure 5. FB Pin Voltage vs. Temperature
1.3
1.3
1.2
1.2
1.1
1.0
0.9
4 LEDs
0.8
1
2
3
4
5
6
INPUT VOLTAGE (V)
Figure 6. Switching Frequency vs. Input
Voltage
1.1
LOAD = 20 mA
1.0
0.9
LOAD = 3 LEDs
VIN = 3.6 V
0.8
−50 −25
0
25
50
75 100
TEMPERATURE (°C)
Figure 7. Switching Frequency vs.
Temperature
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