TPA005D02
2-W STEREO CLASS-D AUDIO POWER AMPLIFIER
SLOS227C – AUGUST 1998 – REVISED MARCH 2000
APPLICATION INFORMATION
class D effect on battery life
Battery operations for class D amplifiers versus linear amplifiers have similar power supply savings results. The
essential contributing factor to longer battery life is lower RMS supply current. Figure 21 compares the
TPA005D02 supply current to the supply current of the TPA0202, a 2-W linear device, while playing music at
different peak voltage levels.
SUPPLY CURRENTS
vs
PEAK OUTPUT VOLTAGE AND PEAK OUTPUT POWER
400
350
300
250
TPA0202
200
150
100
TPA005D02
50
0
3.5
3.06
Peak Output Voltage (V)
Peak Output Power (W)
1
1.5
0.56
2
1
2.5
1.56
3
2.25
4
4
0.25
Figure 21. Supply Current vs Peak Output Voltage of TPA005D02 vs TPA0202 With Music Input
Thisplotshowsthatalinearamplifierhasapproximatelythreetimesmorecurrentdrawatnormallisteninglevels
than a class D amplifier. Thus, a class D amplifier has approximately three times longer battery life at normal
listening levels. If there is other circuitry in the system drawing supply current, that must also be taken into
account when estimating battery life savings.
20
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TI [ TEXAS INSTRUMENTS ]
