I2S Audio Breakout Hookup Guide

Contributors: Alex the Giant
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Hardware Overview

The I2S audio breakout converts the digital audio signals using the I2S standard to an analog signal and amplifies the signal using a class D amplifier. The board can be configured to output only the left channel, right channel, or both. For more information about how to configure the board, refer to the Jumper Selection section below.

I2S Audio Breakout Board Top View

Board Specs

Supply Voltage Range2.5V - 5.5V.
Output Power3.2W into 4Ω at 5V.
Output Channel SelectionLeft, Right, or Left/2 + Right/2 (Default).
Sample Rate8kHz - 96kHz.
Sample Resolution16/32 bit.
Quiescent Current2.4mA.
Additional FeaturesFilterless Class D outputs, no MCLK required, click and pop reduction, short-circuit and thermal protection.

Pin Descriptions

The SparkFun I2S audio breakout board is fairly simple, requiring only a few pin connections to get the board working.

Highlight of Input Connections


Pin LabelDescription
LRCLKFrame clock (left/right clock) input.
BCLKBit clock input.
DINSerial data input.
GAINGain setting. Can be set to +3/6/9/12/15dB. Set to +9dB by default.
SDShutdown and channel select. Pull low to shutdown, or use the jumpers to select the channel output (see jumper selection for more information).
GNDConnect to ground
VDDPower input. Must be between 2.5 and 5.5VDC.


The output is where you'll connect your speaker.

Highlight of Output Connections

Pin LabelDescription
+Positive speaker output.
-Negative speaker output.

Speaker wire can either be soldered directly to the output pads, but if screw terminals are more your style, you can use our 3.5mm screw terminals.

Screw Terminals 3.5mm Pitch (2-Pin)

Screw Terminals 3.5mm Pitch (2-Pin)


Jumper Selection

By default the board is configured in "mono" operation, meaning the left and right signals are combined together to drive a single speaker.

Highlight Of Jumper Selection

If you want a separate speaker for the left and right audio channels you'll first need to cut the mono jumper as pictured below.

Mono Trace Jumper Cut

To configure the board to respond to a specific audio channel, you'll need to close the stereo jumper as shown below.

Single Channel Select Jumper

Gain Selection

In addition to being able to select the audio channel output, the gain can also be configured in a few ways. The gain of the amplifier can be configured from as low as +3dB to as high as +15dB. While the channel selection can be configured on board, the gain however is controlled externally using the gain pin. By default, the board is configured for +9dB, but can be changed using the table below.

Gain (dB)Gain Pin Connection
15Connected to GND through a 100kΩ resistor.
12Connected to GND.
9Unconnected (Default).
6Connected to VDD.
3Connected to VDD through a 100kΩ resistor.