FSP3303 datasheet(5/10 Pages) FOSLINK

5 / 10 page

4 & 6 CHANNEL CHARGE PUMPS FOR WHITE LED BIAS

2007-4-10

5/10

FSP3302/FSP3303

DAC, and therefore the LED current, by 1dB. Once the maximum current level of 0dB is reached, an additional high

to low transition on EN/PROG resets the DAC level to its minimum value of -31dB. Figure 2 demonstrates the

EN/PROG serial protocol.

Figure2. EN/PROG Serial Protocol

To ensure proper DAC initialization, the first low pulse after programming is completed should be at least 5µs.

SOFT START

When enabled, the FSP3302/FSP3303 operate in a low power state for 330µs (tSS) to limit inrush current. After this

time has expired, the devices operate in full-power mode.

THERMAL SHUTDOWN

In order to protect themselves under thermal overload and short circuit conditions, the FSP3302/FSP3303

incorporate thermal shutdown circuitry that monitors the die temperature and disables the IC if it exceeds 160°C.

TYPICAL PERFORMANCE CHARACTERISTICS

(

Circuit of Figure 1, VIN = 3.5V, TA = 25°C unless otherwise specified.)

30dB

29dB

OFF

31dB

30dB

29dB

28dB

tHIGH

tLOW

tOFF

t > tFINISH

tLOW1

FSP3303 Datasheet(PDF) 5 Page - FOSLINK SEMICONDUCTOR CO.,LTD