BJT RthJA value: Conditions of measurement?

[eem2am]

Hello

For BC817-40 , on first page of datasheet there is a RthJA value given of 357C/W

It is not clear whether or not this is for the case of mounting on PCB of are 40mm * 40mm.

Do you know what is the likely RthJA of BC817-40, when connected to no more copper than 0.8mm tracks coming to the B,C, & E pins?

BC817-40 Datasheet
http://www.datasheetcatalog.org/datasheet/fairchild/BC817-40.pdf

 

[keith1200rs]

It will be 375C/W when mounted to 40x40mm of PCB. The asterisk is on the column, implying the not applies to all values in the column.

Philips quote 500C/W with "standard footprint" so that would be a reasonable guide.



Keith.