Datasheet

TPA311

350-mW MONO AUDIO POWER AMPLIFIER

SLOS207C – JANUARY 1998 – REVISED MAY 2003

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

APPLICATION INFORMATION

headroom and thermal considerations (continued)

This is valuable information to consider when attempting to estimate the heat dissipation requirements for the

amplifier system. Comparing the absolute worst case, which is 350 mW of continuous power output with 0 dB

of headroom, against 12 dB and 15 dB applications drastically affects maximum ambient temperature ratings

for the system. Using the power dissipation curves for a 5-V, 8-Ω system, the internal dissipation in the TPA311

and maximum ambient temperatures is shown in Table 3.

Table 3. TPA311 Power Rating, 5-V, 8-Ω, BTL

PEAK OUTPUT POWER

(mW)

AVERAGE OUTPUT

POWER

DISSIPATION

MAXIMUM AMBIENT

TEMPERATURE

(mW) POWER

DISSIPATION

(mW)

0 CFM SOIC 0 CFM DGN

350 350 mW 600

46°C 114°C

350 175 mW (3 dB) 500

64°C 120°C

350 88 mW (6 dB) 380

85°C 125°C

350 44 mW (9 dB) 300

98°C 125°C

350 22 mW (12 dB) 200

115°C 125°C

350 11 mW (15 dB) 180

119°C 125°C

Table 3 shows that the TPA311 can be used to its full 350-mW rating without any heat sinking in still air up to

46°C.