CAT4237 Datasheet, PDF (5/13 Pages) Catalyst Semiconductor – High Voltage CMOS Boost White LED Driver

CAT4237
Typical Characteristics
V_IN = 3.6V, C_IN = 4.7uF, C_OUT = 0.22µF, L = 33µH with 8 LEDs at 20mA, T_AMB=25ºC, unless otherwise specified.
Quiescent Current vs. VIN (Not Switching)
140
120
100
80
60
40
VFB =0.4V
20
(not switching)
0
2.7 3.0 3.3 3.6 3.9 4.2 4.5 4.8
INPUT VOLTAGE [V]
Quiescent Current vs. VIN (Switching)
2.0
1.5
1.0
0.5
0.0
2.5 3.0 3.5 4.0 4.5 5.0
INPUT VOLTAGE [V]
FB Pin Voltage vs. Supply Voltage
315
8LEDs at 20mA
310
VOUT= 26V
305
300
295
290
285
2.7 3.0 3.3 3.6 3.9 4.2 4.5 4.8
INPUT VOLTAGE [V]
FB Pin Voltage vs. Output Current
315
310
8 LEDs
305
300
295
290
285
0
5 10 15 20 25 30
OUTPUT CURRENT [mA]
Switching Frequency vs. Supply Voltage
1040
Switching Waveforms
1020
1000
980
960
2.7 3.0 3.3 3.6 3.9 4.2 4.5 4.8
INPUT VOLTAGE [V]
© 2005 Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
5 of 13
Doc. No. 5013, Rev. A