TDA7269ASA Datasheet, PDF (7/11 Pages) STMicroelectronics – 14W+14W STEREO AMPLIFIER WITH MUTE & ST-BY

TDA7269ASA
5 HEAT SINK DIMENSIONING:
In order to avoid the thermal protection intervention, that is placed approximatively at T_j = 150°C, it is im-
portant the dimensioning of the Heat Sinker R_Th (°C/W).
The parameters that influence the dimensioning are:
– Maximum dissipated power for the device (P_dmax)
– Max thermal resistance Junction to case (R_{Th j-c})
– Max. ambient temperature T_{amb max}
– Quiescent current I_q (mA)
5.1 Example:
V_CC = ±16V, R_load = 8ohm, R_{Th j-c} = 3.9 °C/W , T_{amb max} = 50°C
P_dmax = (N° channels) · _Π------₂²----^V_â‹---_R-^c---^cl--_o2---_a---_d- + I_q ⋅ V_cc
P_dmax = 2 · ( 6.49 ) + 0.84 = 14 W
(Heat Sinker) R_{Th c-a} = ¹----⁵---⁰-----–_P-----_d^T----^am---^m-_a---_xb-----^m----^a--^x- – R_{Th j-c} = -¹---⁵---⁰-₁----₄^–-----5---⁰-- – 3.9 = 3°C /W
In figure 10 is shown the Power derating curve for the device.
Figure 10. Power derating curve
25
20
15
10
5
0
0
(a)
(b)
(c)
a) Infinite Heatsink
b) 3.0 °C/ W
c) 5.0 °C/ W
40
80
120
160
Tamb (°C)
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