TLC5910 Datasheet, PDF (22/30 Pages) Texas Instruments – LED DRIVER

TLC5910
LED DRIVER
SLLS392 – NOVEMBER 1999
PRINCIPLES OF OPERATION
power supply
The followings should be taken into consideration:
D VCCLOG, VCCANA and VCCLED should be supplied by a single power supply to minimize voltage
differences between these terminals.
D The bypass capacitor should be located between the 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.
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
4.7
3.2
2.4
1.48
0
0
–20 0
25
85
TA – Free–Air Temperature – °C
† _{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
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