The TPA0242 Audio Power Amplifier Evaluation Module
3-4
Details
Figure 3–3.TPA0242 EVM Schematic Diagram
R4
100 kΩ
C12
10 µF
GNDGND
RLINEINPCB ENABLE
SHUTDOWNVOLUME
ROUT+LOUT+
ROUT–LOUT–
SE/BTLLIN
PC–BEEPBYPASS
GNDGND
RHPINLLINEIN
VDD
LHPIN
PVDD
PVDD
CLKRIN
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 µFR3
0 Ω
R LINE –
R OUT +
R HP
VDD
ROUT–
SE/BTL
TPA0242
C12
0.47 µF
C9
0.47 µF
L IN +
C2
0.47 µF
R IN +
GND
C8
0.47 µF
C7
0.47 µF
L LINE –
CCW
VDD
R2
50 kΩ
VDD
R1
100 kΩ
C1
0.47 µF
SHUTDOWN
SHUTDOWN
C3
0.47 µF
C10
10 µF
GND
C5
0.1 µF
TP1
C11
0.47 µF
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.