TLK2201A, TLK2201AI

ETHERNET TRANSCEIVERS

SLLS572 – JUNE 2003

17

POST OFFICE BOX 655303

APPLICATION INFORMATION

designing with PowerPAD (continued)

It is recommended that there be a thermal land, which is an area of solder-tinned-copper, underneath the

PowerPAD package. The thermal land varies in size depending on the PowerPAD package being used, the PCB

construction, and the amount of heat that needs to be removed. In addition, the thermal land may or may not

contain numerous thermal vias depending on PCB construction.

Other requirements for thermal lands and thermal vias are detailed in the TI application note PowerPAD

Thermally Enhanced Package Application Report, TI literature number SLMA002, available via the TI Web

Figure 13. Example of a Thermal Land

For the TLK2201A, this thermal land must be grounded to the low-impedance ground plane of the device. This

improves not only thermal performance but also the electrical grounding of the device. It is also recommended

that the device ground pin landing pads be connected directly to the grounded thermal land. The land size must

be as large as possible without shorting device signal pins. The thermal land may be soldered to the exposed

PowerPAD using standard reflow soldering techniques.

While the thermal land may be electrically floated and configured to remove heat to an external heat sink, it is

recommended that the thermal land be connected to the low-impedance ground plane for the device. More

information may be obtained from the TI application note PHY Layout, TI literature number SLLA020.