Using the TPA6011A4 EVM With the
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 TPA6011A4.
-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
When S3 is set to the power amplifier position (U2 – U4), the headphone jack is connected to the TPA6011A4 power amplifier 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).
-To keep the TPA6011A4 amplifier outputs separated, set switch S3 to the headphone amplifier position (U5) and use the speaker outputs (J7, J8, and J9).
-To route the TPA6011A4 amplifier outputs to the headphone output jack (J10), set switch S3 to the power amplifier position (U2 – U4). Uuse this setting only if the TPA6011A4 EVM is to drive
3.3.4Mute (Shutdown)/Mode
The TPA6011A4 EVM is equipped with a shutdown control input pin. When this input is pulled to ground, the TPA6011A4 amplifier IC on the module enters the shutdown mode and dissipates very little power. While in the shutdown mode, the PC BEEP input is still active. When the EVM control input is tied to GND or allowed to float, normal amplifier operation resumes.
In typical applications, as often found in notebook computers, portable audio products, and such, the internal speakers mute when headphones are plugged into the headphone jack, or internal speakers mute when external speakers are connected. In applications using separate speaker and headphone amplifiers, the one not being used can be shut down to conserve power.
A mode control input pin on the EVM switches the TPA6011A4 amplifier IC between the
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