TLC5910

LED DRIVER

SLLS392 – NOVEMBER 1999

22

POST OFFICE BOX 655303

PRINCIPLES OF OPERATION

power supply

The followings should be taken into consideration:

differences between these terminals.

power supply voltage.

GND

Although GNDLOG, GNDANA, and GNDLED are internally tied together, these terminals should be externally

connected to reduce noise influence.

thermal pad

The thermal pad should be connected to GND to eliminate the noise influence when it is connected to the bottom

side of IC chip. Also, the desired thermal effect will be obtained by connecting this pad to the PCB pattern with

better thermal conductivity.

power rating – free-air temperature

2.4

4.7

TA – Free–Air Temperature – °C

0

25

85

–20

1.48

3.2

0

0

† VCCLOG=VCCANA=VCCLED=5.0V, IOLC = 80mA, ICC is typical value.

NOTES: A. IC is mounted on PCB.

PCB size: 102

× 76 x 1.6 [mm3], four layers with the internal two layer being plane. The thermal pad is soldered to the PCB pattern

of 10

× 10 [mm2]. For operation above 25°C free-air temperature, derate linearly at the rate of 38.2 mW/°C.

B. The thermal impedance will be varied depending on mounting conditions. Since the PZP package established low thermal

impedance by radiating heat from the thermal pad, the thermal pad should be soldered to the pattern with a low thermal impedance.

C. Consider thermal characteristics when selecting the material for the PCB, since the temperature will rise around the thermal pad.

Figure 10. Power Rating