Hello,
for drive led lamps (12V and 3,8W), I use TSP4H000A so I can have the fault indication and the chip turn-off the output in case of short circuit of overload current.
The led lamps normally are turn-off, some times blink (duty cycle about 50%) for one minute many times by day, rarely stay in on for 1 minute many time a by day.
Now, I'm drawing the PCB layout and, reading the "layout guidelines" of data sheet, I understand it needs to make a good ground plate of the top layer for good thermal dissipation.
On data sheet, the draw shows the ground plate on top layer fill all around the chip and not only below of it. So, there're two islands for the input, output and fault connections by many and many small vias. Because the chip has a small pitch (0,65mm), the vias size is very small. http://www.ti.com/product/tps4h000-q1
If I see the pictures of the evaluation board, I note the ground plate is only above and lateral of chip and the connection to input, output and fault are always on the top layer. This is enough easy to place the routing of that signals. http://www.ti.com/tool/tps4h000evm?keyMatch=tps4h000-q1%20evm&tisearch=Search-EN-Everything
Now, my question is: for my load and its behavior in time, do I need to make the ground plate as suggested on data sheet (big ground plate with two islands) or it's enough the "H" shape ground plate below the chip as shown the pictures of evaluation board?
Thank You and Best Regards
Federico Battaglin
