TLC5902

LED DRIVER

SLLS382 – DECEMBER 1999

16

POST OFFICE BOX 655303

PRINCIPLES OF OPERATION

noise reduction (continued)

power supply

VCCLOG, VCCANA, and PVCC are supplied by a single power supply to minimize voltage differences between

these terminals.

The bypass capacitor is located between power supply and GND to eliminate the variation of power supply

voltage.

GND

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

connected to reduce noise influence.

heat sink pad

The heat sink pad should be connected to GND to eliminate the noise influence since it is connected to the

bottom side of the IC chip. Also, the desired thermal effect is obtained by connecting this pad to the PCB pattern

with better thermal conductivity.

–20

25

85

0

1.48

3.2

4.7

2.4

0

TA – Free-Air Temperature – °C

NOTES: A. IC is mounted on PCB. PCB size: 102

× 76 × 1.6 [mm3], four layers with internal two layer having plane. The thermal pad is soldered

to PCB pattern of 10 mm2. For operation above 25

°C free-air temperature, derate linearly at the rate of 38.2 mW/°C.

VCCLOG = VCCANA = PVCC = 5 V, IOL(C) = 80 mA, ICC is typical value

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

Figure 3. Power Rating