TDA8920C_09 Datasheet, PDF (19/39 Pages) NXP Semiconductors – 2 ´ 110 W class-D power amplifier

NXP Semiconductors
TDA8920C
2 × 110 W class-D power amplifier
13.5 Heatsink requirements
An external heatsink must be connected to the TDA8920C.
Equation 5 defines the relationship between maximum power dissipation before activation
of TFB and total thermal resistance from junction to ambient.
R_th(j–a) = ^T-----^j---^–---_P-^T----^a---^m----^b
(5)
Power dissipation (P) is determined by the efficiency of the TDA8920C. Efficiency
measured as a function of output power is given in Figure 20. Power dissipation can be
derived as a function of output power as shown in Figure 19.
30
P
(W)
(1)
20
mbl469
(2)
10
(3)
(4)
(5)
0
0
20
40
60
80
100
T_amb (°C)
(1) R_th(j-a) = 5 K/W.
(2) R_th(j-a) = 10 K/W.
(3) R_th(j-a) = 15 K/W.
(4) R_th(j-a) = 20 K/W.
(5) R_th(j-a) = 35 K/W.
Fig 9. Derating curves for power dissipation as a function of maximum ambient
temperature
TDA8920C_2
Product data sheet
Rev. 02 — 11 June 2009
© NXP B.V. 2009. All rights reserved.
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