Texas Instruments TPA0242 User Manual
Page 20
The TPA0242 Audio Power Amplifier Evaluation Module
3-4
Details
Figure 3–3. TPA0242 EVM Schematic Diagram
R4
100 k
Ω
C12
10
µ
F
GND
GND
RLINEIN
PCB ENABLE
SHUTDOWN
VOLUME
ROUT+
LOUT+
ROUT–
LOUT–
SE/BTL
LIN
PC–BEEP
BYPASS
GND
GND
RHPIN
LLINEIN
VDD
LHPIN
PVDD
PVDD
CLK
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
0.47
µ
F
R3
0
Ω
R LINE –
R OUT +
R HP
VDD
ROUT–
SE/BTL
TPA0242
C12
0.47
µ
F
C9
0.47
µ
F
L IN +
C2
0.47
µ
F
R IN +
GND
C8
0.47
µ
F
C7
0.47
µ
F
L LINE –
CCW
VDD
R2
50 k
Ω
VDD
R1
100 k
Ω
C1
0.47
µ
F
SHUTDOWN
SHUTDOWN
C3
0.47
µ
F
C10
10
µ
F
GND
C5
0.1
µ
F
TP1
C11
0.47
µ
F
PCBEEP
VDD
S2
CW
C6
47 nF
S3
HP/LINE
S4
SE/BTL
3.2.1
TPA0242 Audio Amplifier IC
The TPA0242 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
TPA0242 amplifier IC data sheet, TI literature number SLOS287.