TDA8133_03 Datasheet, PDF (9/13 Pages) STMicroelectronics – +5.1 V AND +8 V DUAL-VOLTAGE REGULATOR WITH DISABLE AND RESET FUNCTIONS

TDA8133/D
POWER DISSIPATION AND LAYOUT INDICATIONS
5 POWER DISSIPATION AND LAYOUT INDICATIONS
The power is mainly dissipated by the two device buffers. It can be calculated by the equation:
P = (V_IN1-V_O1) x I_O1 + (V_IN2-V_O2) x I_O2
The following table lists the different R_thJA values of these packages with or without a heat sink and
the corresponding maximum power dissipation assuming:
q Maximum Ambient Temperature = 70° C
q Maximum Junction Temperature = 140° C
Device
TDA8133
TDA8133D
Heat Sink
No
Yes
No
Yes
R_thJA in °C/W
50
20
56 to 40
32
P_MAX in W
1.4
3.5
1.25 to 1.75
2.2
Figure 7: Thermal Resistance (Junction-to-Ambient) of DIP16 Package without Heat Sink
To optimize the thermal conductivity of the copper
60
layer and the exchanges with the air, the solder
must cover the maximum amount of this area.
55
Test Board with
50
“On Board” square heat sink area.
45
40
0
2
4
6
8
10 12
Copper area (cm²) (35 µm plus solder) Board is face-down
Figure 8: Metal plate mounted near the TDA8133D for heat sinking
Top View
Bottom View
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