Philips TDA2611A

November 1982 4

Philips Semiconductors Product speciﬁcation

5 W audio power ampliﬁer TDA2611A

Fig.2 Power derating curves.

HEATSINK EXAMPLE

Assume VP= 18 V; RL= 8 Ω; Tamb = 60 °C maximum; Tj= 150 °C (max. for a 4 W application into an 8 Ω load, the

maximum dissipation is about 2,2 W).

The thermal resistance from junction to ambient can be expressed as:

Since Rth j-tab = 11 K/W and Rth tab-h = 1 K/W, Rth h-a = 41 − (11 + 1) = 29 K/W.

Rth j-a Rth j-tab Rth tab-h Rth h-a 150 60–

22,

---------------------- 41 K/W.==++=