ST-PLC-AFE datasheet(41/58 Pages) STMICROELECTRONICS

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ST-PLC-AFE

Application information

10.2

Thermal considerations

When the ST-PLC-AFE transmits information on low-impedance, power-line domains, more

power is dissipated which leads to junction temperature increase. If the junction temperature

reaches 160 °C, the thermal protection latches to freeze the transmission. This is why good

PCB design and correct management of the heat flow from the ST-PLC-AFE is necessary to

minimize losses and decrease system temperature, extend device operating life, and

maximize performance.

10.2.1

Maximizing the heat flow from the junction temperature to the PCB

The package of the ST-PLC-AFE is a QFN48-pin with an exposed PAD. The majority of heat

is evacuated through the exposed PAD, on the underside of the package, which is why the

package must be soldered to the PCB thermal pad with the lowest resistivity possible. The

thermal pad should be the same size as the exposed pad and multiple vias.

10.2.2

Reducing the PCB thermal resistance

This can be done by increasing the number of layers, using thicker copper, and/or

increasing the PCB area. The figures below show PCB examples of thermal resistance as a

function of the number of PCB layers, PCB area, and copper thickness.

Figure 42. Thermal resistance as a function of the number of layers in the PCB

ST-PLC-AFE 数据表(PDF) 41 Page - STMicroelectronics