The TPA0242 Audio Power Amplifier Evaluation Module
Figure 3±3. TPA0242 EVM Schematic Diagram
HP/LINE
L OUT +
L LINE ±
L HP
VDD
GND
R IN +
L OUT ±
L IN +
R2 | | | | | | | C1 |
50 kΩ | 1 | | 24 | | | |
| | R1 | 0.47 µF |
VDD | GND | | GND | |
| | 100 kΩ | |
CW | TPA0242 | | VDD |
2 | | 23 | | | |
S3 | PCB ENABLE | RLINEIN | | | | |
| | | | |
TP1 | 3 | | 22 | | | | S1 |
CCW | VOLUME | SHUTDOWN | | | | |
| | | | |
S4 | 4 | | 21 | | SHUTDOWN |
| | | | |
| LOUT+ | | ROUT+ | | | C3 | |
SE/BTL | 5 | | 20 | | | |
| | | 0.47 µF | |
C7 | LLINEIN | | RHPIN | | | | |
| | | | | | |
0.47 µF | 6 | | 19 | | | | |
C8 | LHPIN | | VDD | | C4 | R3 | |
| | | | 0.47 µF | 0 Ω |
0.47 µF | 7 | | 18 | | | | |
C12 | PVDD | | PVDD | | | | |
8 | | 17 | C6 | | | |
10 µF | | | | C10 |
RIN | | CLK | | C5 | |
| | | |
| | | | 47 nF | | 10 µF |
| 9 | | 16 | 0.1 µF |
| | |
C2 | LOUT± | | ROUT± | | | | |
| | | | | | |
0.47 µF | 10 | | 15 | | | | |
| | | | | |
| LIN | | SE/BTL | | | | |
| 11 | | 14 | PCBEEP | | |
C12 | BYPASS | | PC±BEEP | | R4 |
| | | | | | 100 kΩ |
0.47 µF | 12 | | 13 | | S2 |
| C11 | |
C9 | GND | | GND | | VDD | |
| | | 0.47 µF | |
0.47 µF | | | | | | | |
R LINE ±
SHUTDOWN
R OUT +
R HP
VDD
GND
ROUT±
SE/BTL
3.2.1TPA0242 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.
