Datasheet

Operation

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2 Operation

This section describes how to operate the TPA2038D1EVM.

2.1 Quick Start for Stand-Alone Operation

Use the following steps when operating the TPA2038D1EVM stand-alone or when connecting the EVM

into existing circuits or equipment.

2.1.1 Power and Ground

1. Ensure that the external power sources are set to OFF.

2. Set the power supply voltage between 2.5 V and 5.5 V. When connecting the power supply to the

EVM, attach the ground connection to the GND header pin first, and then connect the positive supply

to the VDD header pin. Verify that the connections are made to the correct header pins.

2.1.2 Inputs and Outputs

2.1.2.1 Audio

1. Ensure that the audio source is set to the minimum level.

2. Connect the audio source to the RCA input socket, IN. For differential audio input sources, leave the

JP IN header open. For single-ended sources, insert JP IN jumper, connecting IN- to ground through

input capacitor C2.

3. Connect a speaker (4 Ω-32 Ω) between the output banana jacks OUT+ and OUT-.

2.1.2.2 Enable Control

The TPA2038D1 has an active-high enable pin EN. A logic high on this pin places the device in the

operating mode, and a logic low on this pin places the device in the shutdown mode. Press and hold

pushbutton S1 on the EVM to place the TPA2038D1 in shutdown mode. Release pushbutton S1 to

resume normal operation.

2.1.2.3 Gain

The header labeled GAIN set the TPA2038D1 Class-D amplifier gain. R2 pulls up the TPA2038D1 gain

pin (ball A2) to VDD when the 2 mm jumper is removed.

1. For +12 dB gain, connect a jumper to the GAIN header.

2. For +6 dB gain, leave the GAIN header open.

2.1.2.4 Output filter

Test points TPOUT+ and TPOUT- are low-pass filtered TPA2038D1 OUT+ and OUT- outputs. Populate

filter components R4, R5, C9 and C10 (see Table 1 for typical components) to use the filter. This filter

reduces measurment error from TPA2038D1 Class-D switching when using equipment such as the Audio

Precision.

2.2 Power Up

1. Verify the correct connections as described in Sections 2.1.1 and 2.1.2.

2. Verify the voltage setting of the power supply is between 2.5 V and 5.5 V, and turn on the power

supply. Proper operation of the EVM begins.

3. Adjust the audio signal source as needed.

TPA2038D1 Audio Power Amplifier Evaluation Module SLOU298– August 2011

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