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

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

(

30dB

29dB

OFF

OFF

31dB

31dB

30dB

29dB

28dB