Texas Instruments TPA0122, User Manual, Page: 20 / 34

The TPA0122 Audio Power Amplifier Evaluation Module
3-4 Details
Figure 3–3. TPA0122 EVM Schematic Diagram
R5
100 k
Ω
C12
10
µ
F
GND GND
RLINEIN GAIN0
SHUTDOWN GAIN1
ROUT+ LOUT+
ROUT– LOUT–
SE/BTL LIN
PC–BEEP BYPASS
GND GND
RHPIN LLINEIN
VDD LHPIN
PVDD PVDD
PCB ENABLE RIN
10
9
12
11
6
5
8
7
2
1
4
3
23
22
21
20
19
18
17
16
15
14
13
24
S1
L OUT –
L OUT +
L HP
VDD
C4
0.1
µ
F
R4
0
Ω
R LINE –
R OUT +
R HP
VDD
ROUT–
SE/BTL
TPA0122
C11
0.47
µ
F
C8
0.47
µ
F
L IN +
C2
0.47
µ
F
R IN +
GND
C7
0.47
µ
F
C6
0.47
µ
F
L LINE –
S2
VDD
S3
R3
100 k
Ω
R2
100 k
Ω
VDD
R1
100 k
Ω
C1
0.47
µ
F
SHUTDOWN
SHUTDOWN
C3
0.47
µ
F
C9
10
µ
F
GND
C5
0.1
µ
F
TP1
C10
0.47
µ
F
TP2
VDD
S4
3.2.1 TPA0122 Audio Amplifier IC
The TPA0122 audio amplifier IC (Figure 3–4) is a CMOS device intended
primarily for bridge-tied load (BTL) operation in battery-powered applications.
It is supplied in a very small 24-pin TSSOP thermal surface-mount package
and has been designed to operate from low supply voltages (between
approximately 4.5 V and 5.5 V). Typical applications include portable
computers and multimedia systems.
The IC includes two separate amplifier channels, each of which can operate
in either the bridged-tied load (BTL) mode or the single-ended mode as
selected by the SE/BTL pin. In the BTL mode, the line inputs are automatically
selected and the two output lines of each channel operate as mirror images
of each other for increased power. The speaker load is connected directly
across OUT+ and OUT–, and neither line is connected to ground. BTL
operation provides many benefits, including quadruple the output power of
single-ended operation and no need for bulky output coupling capacitors.
In the single-ended mode, the headphone inputs are automatically selected
and the speaker load is connected between the OUT+ terminal, through an
output coupling capacitor, to system ground. For more information, see the
TPA0122 amplifier IC data sheet, TI Literature Number SLOS247.