Place the decoupling capacitor near the VCC and GND terminals.
Route the GND pattern as widely as possible for large GND currents. Maximum GND current is approximately 1.53 A.
Routing between the LED cathode side and the
device OUTXn should be as short and straight as possible to reduce wire
inductance. Route them on LED layer to guarantee the continous GND plane in IC
layer.
The PowerPAD must be connected to the GND layer because the pad is not internally connected to GND and should be connected to a heat sink layer to reduce device temperature.
The GND plane should be as large as possible, especially for the two-layer board.
The reason is that the two-layer board normally couldn't provide a continuous
GND plane beneath the chip for thermal dissipation. The only area for thermal
dissipation is the GND plane around the chip.