Datasheet

CAT3649
http://onsemi.com
8
TYPICAL PERFORMANCE CHARACTERISTICS
(V
IN
= 3.6 V, PWM = V
IN
, I
OUT
= 120 mA (6 LEDs at 20 mA), C
IN
= C
OUT
= C
1
= C
2
= 1 mF, C
PWM
= 47 nF,
T
AMB
= 25°C unless otherwise specified.)
Figure 22. Foldback Current Limit Figure 23. LED Current vs. LED Pin Voltage
LOAD CURRENT (mA) LED PIN VOLTAGE (mV)
300250200150100500
0
0.5
1.0
2.0
2.5
3.0
3.5
4.0
300250200150100500
0
5
10
15
20
25
30
Figure 24. Dimming Waveform Figure 25. 20 kHz PWM Dimming,
10% Duty Cycle
Figure 26. LED Current vs. PWM Duty Cycles Figure 27. 1 kHz PWM Duty Cycle Increasing
10% to 50%
DUTY CYCLE (%)
100101
0
1
10
OUTPUT VOLTAGE (V)
LED CURRENT (mA)
LED CURRENT (mA)
1.5
1x Mode
25 mA
20 mA
200 kHz
100 kHz
50 kHz