Diodes AP2502 - Manual (Page 8)

Data Sheet
4-CH Linear Constant Current Sink With Matching AP2502
Oct. 2010 Rev 1. 1 BCD Semiconductor Manufacturing Limited
8
Typical Performance Characteristics (Continued)
Figure 12. LED Current (Note 2) Figure 13. Internal Oscillator Working at Low Frequency
(V
IN
=4V, V
EN
=0 to 3.6V, Duty cycle=50%, f
PWM
=1kHz) (V
IN
=4V, V
EN
=0 to 3.6V, Duty cycle=50%, f
PWM
=0.1kHz)
Note 2: Chopper offset-canceling technology is adopted to get good current matching, I
LED
=[(I
1
+I
2
)/2]*duty.
V
EN
2V/div
I
LED
10mA/div
Time 400
µs/div
I
1
I
2
Time 2ms/div
V
EN
2V/div
I
LED
10mA/div