E910.27A Datasheet, PDF (33/50 Pages) ELMOS Semiconductor AG – External Adjustable High Efficiency PFM Step-Down Converter

- Preliminary -
E910.27A
50
45
TSSOP24 ADT-1 Package
70µm Cu, Copper Clad PC-Board
40
35
30
25
5
10 15 20 25 30 35 40 45 50 55
Heat Sink Area [cm²]
Figure 8.1.7-1: Typical Thermal Resistance (RTAJ) versus PC-Board Area
Always use a ground plane under the step-down converter to minimise interplane coupling and provide the
required heat sinking. The typically thermal resistance for a given PC-board area can be read in the above
diagram. By further reducing of the thermal resistance due to an additional external heat sinking (e.g. case)
a maximum power loss of about 1.6W is possible.
ELMOS Semiconductor AG
Specification 33 / 50
03SP0357E.00 05.09.2006