TDA8922C Datasheet, PDF (19/40 Pages) NXP Semiconductors – 2 X 75 W class-D power amplifier

NXP Semiconductors
TDA8922C
2 × 75 W class-D power amplifier
Equation 5 defines the relationship between maximum power dissipation before activation
of TFB and total thermal resistance from junction to ambient.
(5)
R_th(j–a) = -^T----^j---^–---_P-^T----^a---^m----^b
Power dissipation (P) is determined by the efficiency of the TDA8922C. 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
TDA8922C_1
Product data sheet
Rev. 01 — 7 September 2009
© NXP B.V. 2009. All rights reserved.
19 of 40