Philips Semiconductors
5 W audio power amplifier
Product specification
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:
Rth j-a = Rth j-tab + Rth tab-h + Rth h-a = -1---5---20---,--–-2----6---0-- = 41 K/W.
Since Rth j-tab = 11 K/W and Rth tab-h = 1 K/W, Rth h-a = 41 − (11 + 1) = 29 K/W.
November 1982
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