TPA0102 Datasheet, PDF (34/38 Pages) Texas Instruments – 1.5-W STEREO AUDIO POWER AMPLIFIER

TPA0102
1.5-W STEREO AUDIO POWER AMPLIFIER
SLOS166E – MARCH 1997 – REVISED MARCH 2000
APPLICATION INFORMATION
mute and shutdown modes
The TPA0102 employs both a mute and a shutdown mode of operation designed to reduce supply current, I_DD,
to the absolute minimum level during periods of nonuse for battery-power conservation. The SHUTDOWN input
terminal should be held low during normal operation when the amplifier is in use. Pulling SHUTDOWN high
causes the outputs to mute and the amplifier to enter a low-current state, I_DD < 1 µA. SHUTDOWN or MUTE
IN should never be left unconnected because amplifier operation would be unpredictable. Mute mode alone
reduces I_DD < 1 mA.
Table 3. Shutdown and Mute Mode Functions
INPUTS†
SE/BTL
HP/LINE
MUTE IN
Low
Low
Low
X
X
—
X
Low
High
X
High
Low
High
Low
Low
High
High
Low
† _{Inputs should never be left unconnected.}
X = do not care
SHUTDOWN
Low
High
—
Low
Low
Low
OUTPUT
MUTE OUT
Low
—
High
Low
Low
Low
AMPLIFIER STATE
INPUT
OUTPUT
L/R Line
BTL
X
Mute
X
L/R HP
L/R Line
Mute
BTL
SE
L/R HP
SE
using low-ESR capacitors
Low-ESR capacitors are recommended throughout this applications section. A real (as opposed to ideal)
capacitor can be modeled simply as a resistor in series with an ideal capacitor. The voltage drop across this
resistor minimizes the beneficial effects of the capacitor in the circuit. The lower the equivalent value of this
resistance the more the real capacitor behaves like an ideal capacitor.
5-V versus 3.3-V operation
The TPA0102 operates over a supply range of 3 V to 5.5 V. This data sheet provides full specifications for 5-V
and 3.3-V operation, as these are considered to be the two most common standard voltages. There are no
special considerations for 3.3-V versus 5-V operation as far as supply bypassing, gain setting, or stability goes.
For 3.3-V operation, supply current is reduced from 19 mA (typical) to 13 mA (typical). The most important
consideration is that of output power. Each amplifier in TPA0102 can produce a maximum voltage swing of
V_DD – 1 V. This means, for 3.3-V operation, clipping starts to occur when V_O(PP) = 2.3 V as opposed to
V_O(PP) = 4 V at 5 V. The reduced voltage swing subsequently reduces maximum output power into an 8-Ω load
before distortion becomes significant.
Operation from 3.3-V supplies, as can be shown from the efficiency formula in equation 4, consumes
approximately two-thirds the supply power for a given output-power level than operation from 5-V supplies.
When the application demands less than 500 mW, 3.3-V operation should be strongly considered, especially
in battery-powered applications.
34
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265