Texas Instruments TPA0103 manual Inputs and Outputs

Inputs and Outputs

3.3.6Inputs and Outputs

The TI Plug-N-Play Audio Amplifier Evaluation Platform is equipped with several standard conectors for audio inputs and outputs.

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 platform audio signal input jacks (J3, J4, and J5) are of the closed-circuit type, grounding the signal input lines when no plugs are inserted.

3.3.6.2Outputs

When the TPA0103 EVM is installed, amplified audio output signals leave the platform through the negative left and right compression connectors for stripped speaker wires (J8) and through a miniature (1/8″ ) stereo phone jack (J10), for headphones.

The TPA0103 EVM BTL center channel audio output from amplifier IC leave the platform via the left and right negative (black) compression connectors of J8. The positive (red) connectors of J8 are not used. Each output is isolated from system ground allowing the TPA0103 center channel power amplifier to operate in the highly-efficient bridge-tied load configuration for driving a speaker.

The platform 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 TPA0103 single-ended left and right stereo headphone output signals are routed to J10 by S3, signals output via J10 are returned to platform ground when a plug is inserted (Figure 3±8).

Figure 3±8. Typical Headphone Plug

Left Right GND

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