Inputs and Outputs
3.3.6Inputs and Outputs
The TI
3.3.6.1Inputs
In most cases, audio signals enter the platform through either a pair of RCA phono jacks (J3 and J5) or a miniature (1/8″ ) stereo phone jack (J4). Certain signal conditioning and amplifier EVMs, however, may have additional signal input connectors mounted on the module circuit board. The TPA0242 EVM has a special PC BEEP signal input pin (TP2) on the top of the module PCB.
The platform audio signal input jacks (J3, J4, and J5) are of the
3.3.6.2Outputs
Amplified audio output signals leave the platform through left and right RCA phono jacks (J7 and J9), left and right pairs of compression connectors for stripped speaker wires (J8), and optionally, through a miniature (1/8″ ) stereo phone jack (J10), for headphones.
The audio output lines from the power amplifiers are separate all the way to the edge of the platform (output jacks J7, J8, and J9) Ð the OUT± lines from the power amplifier sockets are not tied to each other or to platform ground. This allows the TPA0242 power amplifier EVM to operate in the
The headphone jack (J10) is capacitively coupled to source select switch S3, which connects J10 to the output lines of either the headphone amplifier socket or the power amplifier sockets (Figure 3±6). When the TPA0242 output signal is routed to J10 by S3, signals output via J10 are returned to platform ground when a plug is inserted (Figure 3±8), requiring
Figure 3±8. Typical Headphone Plug
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Details