Using The TPA0103 EVM With the
3.3.3Signal Routing
Signal flow on the platform is controlled by two signal routing switches, as shown in Figure 3±5.
Figure 3±6. Platform Signal Routing and Outputs
R |
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Audio | U1 | |
Signal | ||
Input | ||
Conditioning | ||
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L |
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Off
S2
On
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| + |
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| R | R |
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U2 |
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| ± | J8 |
TPA0103 |
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| |
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| Speaker | |
Amplifier EVM |
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| ||
| ± | Output | ||
| L | L | ||
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| ||
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| + |
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| U2 ± U4 |
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| R |
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U5 | R |
| + |
|
Stereo |
| GND | ± | J10 |
Headphone |
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| Headphone | |
| S3 |
| ||
Amplifier | L |
| ± | Output |
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| + |
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| L |
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| U5 |
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3.3.3.1Signal Conditioning
The audio signal from the input jacks can be applied to the signal conditioning socket (U1) if an EVM is installed there, or socket U1 can be bypassed and the audio input signal applied directly to the inputs of the TPA0103.
-Switch S2 selects signal conditioning or bypasses it.
3.3.3.2Headphone Output Jack
Switch S3 is the source select for the stereo headphone output jack, J10. The headphone jack is capacitively coupled (via 470 μF electrolytics) and can output either the signal from the headphone amplifier in socket U5, or the signal from the TPA0103 power amplifier installed in socket U2, as determined by the setting of headphone source select switch S3.
When S3 is set to the power amplifier position (U2 ± U4), the headphone jack is connected to the TPA0103 left and right OUT+ output lines. When a plug is inserted into the jack, signals output through J10 are returned to platform ground, requiring
Source select switch S3 connects the headphone jack to the output lines of either the headphone amplifier socket U5 or the power amplifier sockets (U2 ± U4).
JTo route the TPA0103
Details