AN1703 datasheet(3/22 Pages) STMICROELECTRONICS

3 / 22 page

AN1703 - APPLICATION NOTE

3/22

What we now have to compute is the TJ value since TC is also an input data related to ambient or case

temperature. To detect the arising junction temperature (TJ), we look at the variation of the forward drop

of the drain-source diode, since this variation is proportional to the change in junction temperature.

3. D2PAK

The D2PAK is a surface mounting version of the standard TO-220 package, with the lead formed and the

tab removed. It has been designed to achieve the high quality and reliability levels required by end users

in the automotive industry.

Figure 2 shows D2PAK and its recommended footprint:

Figure 2: D2PAK and its recommended footprint (all dimensions are in mm)

Figure 3 shows a graph of RTHJ-PCB versus drain pad area from minimum recommended footprint to

10cm2:

Figure 3: RTHJ-PCB versus drain pad area for D

2PAK

100

200

300

400

500

600

700

800

900 1000

FR-4, 2 oz copper board

Minimum recommended footprint

THJ-A

AN1703 Datasheet(PDF) 3 Page - STMicroelectronics