Datasheet

TPA311
350-mW MONO AUDIO POWER AMPLIFIER
SLOS207C – JANUARY 1998 – REVISED MAY 2003
19
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TYPICAL CHARACTERISTICS
Figure 46
P
O
– Output Power – mW
POWER DISSIPATION
vs
OUTPUT POWER
200 600400 8000 1000 1200
V
DD
= 5 V
R
L
= 8 Ω
BTL
400
320
240
160
720
P
D
– Power Dissipation – mW
480
560
640
Figure 47
P
O
– Output Power – mW
POWER DISSIPATION
vs
OUTPUT POWER
50 150100 2000 250 300
V
DD
= 5 V
SE
100
80
60
40
180
P
D
– Power Dissipation – mW
120
140
160
R
L
= 8 Ω
R
L
= 32 Ω
APPLICATION INFORMATION
bridge-tied load versus single-ended mode
Figure 48 shows a linear audio power amplifier (APA) in a BTL configuration. The TPA311 BTL amplifier consists
of two linear amplifiers driving both ends of the load. There are several potential benefits to this differential drive
configuration but initially consider power to the load. The differential drive to the speaker means that as one side
is slewing up, the other side is slewing down, and vice versa. This in effect doubles the voltage swing on the
load as compared to a ground referenced load. Plugging 2 × V
O(PP)
into the power equation, where voltage is
squared, yields 4× the output power from the same supply rail and load impedance (see equation 1).
Power +
V
(rms)
2
R
L
(1)
V
(rms)
+
V
O(PP)
22
Ǹ