beautypg.com

Texas Instruments TPA0202 User Manual

Page 31

background image

Inputs and Outputs

3-15

Details

3.3.6

Inputs and Outputs

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

3.3.6.1

Inputs

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.

3.3.6.2

Outputs

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) — the OUT– lines from
the power amplifier sockets are not tied to each other or to platform ground.
This allows the TPA0202 power amplifier EVM to operate in the highly-efficient
bridge-tied load configuration when driving speakers.

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 – 5). When the TPA0202 output
signal is routed to J10 by S3, signals output via J10 are returned to platform
ground when a plug is inserted (Figure 3 – 7), requiring single-ended operation
of the power amplifiers.

Figure 3–8. Typical Headphone Plug

Left

Right

GND