Datasheet

TPA0202
2-W STEREO AUDIO POWER AMPLIFIER
SLOS205B – FEBRUARY 1998 – REVISED DECEMBER 2000
39
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
APPLICATION INFORMATION
headroom and thermal considerations (continued)
Table 4. TPA0202 Power Rating, 5-V, 3-Ω, Stereo
PEAK OUTPUT POWER
(W)
AVERAGE OUTPUT POWER
POWER DISSIPATION
(W/Channel)
MAXIMUM AMBIENT
TEMPERATURE
2 2 W 1.7 –3°C
2 1000 mW (3 dB) 1.6 6°C
2 500 mW (6 dB) 1.4 24°C
2 250 mW (9 dB) 1.1 51°C
2 120 mW (12 dB) 0.8 78°C
2 63 mW (15 dB) 0.6 96°C
DISSIPATION RATING TABLE
PACKAGE T
A
≤ 25°C DERATING FACTOR T
A
= 70°C T
A
= 85°C
PWP
†
2.7 W 21.8 mW/°C 1.7 W 1.4 W
PWP
‡
2.8 W 22.1 mW/°C 1.8 W 1.4 W
†
This parameter is measured with the recommended copper heat sink pattern on a 1-layer PCB, 4 in
2
5-in × 5-in PCB,
1 oz. copper, 2-in × 2-in coverage.
‡
This parameter is measured with the recommended copper heat sink pattern on an 8-layer PCB, 6.9 in
2
1.5-in × 2-in PCB,
1 oz. copper with layers 1, 2, 4, 5, 7, and 8 at 5% coverage (0.9 in
2
) and layers 3 and 6 at 100% coverage (6 in
2
).
The maximum ambient temperature depends on the heatsinking ability of the PCB system. Using the 0 CFM
and 300 CFM data from the dissipation rating table, the derating factor for the PWP package with 6.9 in
2
of
copper area on a multilayer PCB is 22 mW/°C and 54 mW/°C respectively. Converting this to Θ
JA
:
Θ
JA
1
Derating
1
0.022
45°C W
For 0 CFM :
(19)
To calculate maximum ambient temperatures, first consider that the numbers from the dissipation graphs are
per channel so the dissipated heat needs to be doubled for two channel operation. Given Θ
JA
, the maximum
allowable junction temperature, and the total internal dissipation, the maximum ambient temperature can be
calculated with the following equation. The maximum recommended junction temperature for the TPA0202 is
150 °C. The internal dissipation figures are taken from the Power Dissipation vs Output Power graphs.