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

(VIN=4V, VEN=0 to 3.6V, Duty cycle=50%, fPWM=1kHz)

(VIN=4V, VEN=0 to 3.6V, Duty cycle=50%, fPWM=0.1kHz)

Note 2: Chopper offset-canceling technology is adopted to get good current matching, ILED=[(I1+I2)/2]*duty.

VEN

2V/div

ILED

10mA/div

Time 400

µs/div

I1

I2

Time 2ms/div

VEN

2V/div

ILED

10mA/div