Datasheet

www.ti.com

TPA301

SLOS208E – JANUARY 1998 – REVISED JUNE 2004

Converting dB back into watts:

= 10

PdB/10

= 11 mW (15 dB headroom)

= 22 mW (12 dB headroom)

= 44 mW (9 dB headroom)

= 88 mW (6 dB headroom)

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 TPA301 and

maximum ambient temperatures is shown in Table 2 .

Table 2. TPA301 Power Rating, 5-V, 8-Ω, BTL

MAXIMUM AMBIENT

PEAK OUTPUT

AVERAGE OUTPUT POWER DISSIPATION

TEMPERATURE

POWER

POWER (mW)

(mW)

0 CFM

350 350 mW 600 46°C

350 175 mW (3 dB) 500 64°C

350 88 mW (6 dB) 380 85°C

350 44 mW (9 dB) 300 98°C

350 22 mW (12 dB) 200 115°C

350 11 mW (15 dB) 180 119°C

Table 2 shows that the TPA301 can be used to its full 350-mW rating without any heat sinking in still air up to

46°C.