Creltek I2S Stereo DAC v1.1

The Creltek I2S Stereo DAC features a high-quality 24-bit digital-to-analog converter for stereo audio in I2S format. Left and Right line-level outputs are provided on z pair female RCA phono connectors, which are also wired in parallel with an on-board 3.5mm TRS "stereo headphone" jack. A single row of header pins makes it perfect for breadboard or prototyping use. The analog audio output signals, along with extra grounds, are also brought out on the header pins.

A 1x12 strip of 0.1" spacing machined header pins (pictured) can be included as an option during purchase. RCA cables not included.

This board is based on the Wolfson/Cirrus Logic WM8524 stereo DAC IC. An integrated charge pump provides true 2Vrms line driver outputs from a single 3.3V power supply rail. Ground-referenced outputs and the use of a DC servo eliminate the need for line driving coupling capacitors and effectively eliminate power-up / power-down pops and clicks. Manufacturer-recommended output filters are included on board, and are designed to interface directly with typical (10kΩ impedance) line-level inputs. Care has been taken in routing and component placement to achieve a high-performance, low-noise design.

All common audio sampling rates between 8kHz and 192kHz are supported, using common Master Clock rates. The device interface operates in I2S slave mode, with a choice of Left-Justified, Right-Justified, or I2S bitstream formatting.

NOTE: This is a 3.3V device and is NOT 5V tolerant. The power supply and all connected digital signals must be 3.3V.

Features

• High performance stereo DAC with ground-referenced line driver
• Left and Right RCA output jacks
• 3.5mm TRS "stereo headphone" output jack
• 106dB Signal-to-Noise Ratio (‘A-weighted’)
• -89dB Total Harmonic Distortion @ -1dBFS
• 120dB attenuation when muted
• All common sample rates from 8kHz to 192kHz supported
• Data formats: I2S, Left-Justified, or Right-Justified
• Maximum 1mV DC offset on Line Outputs
• Pop/Click suppressed Power Up/Down Sequencer
• Single +3.3V power supply (±10%)

Connections and Requirements

I2S Audio comprises the following signals:

• Serial Data, connected to "SD" pin on board (aka: SDATA, SDIN, SDOUT, DACDAT, ADCDAT, etc.)
• Serial Clock, connected to "SClk" pin on board (aka: SCK, "Bit Clock" BCLK, etc.)
• Word Select, connected to "WS" pin on board (aka: "Word Clock" WCLK, "Left-Right Clock" LRCLK, etc.)

Additionally, a master clock is required to drive the converter's internal operation, typically at 128x or 256x the Serial Clock frequency:

• Master Clock, connected to "MCLK" pin on board

A Mute pin is provided, which silences the converter outputs and puts the device into low-power mode when pulled LOW. (A pull-up resistor is provided on board, so this pin can be left unconnected if mute functionality is not needed.):

• "Mute" pin, pulled LOW for mute mode, or pulled/floating HIGH for normal operation

Finally, a single hardware control pin is provided to select the bit stream format:

• "Fmt" pin, pulled LOW for Left-Justified, pulled HIGH for I2S, or left floating for Right-Justified.

Pinout Detail

1. "Lo": Left Output
2. "G": Ground (for Left Output)
3. "Ro": Right Output
4. "G": Ground (for Right Output)
5. "Vdd": +3.3V Supply (VDD)
6. "G": Ground / 0V Supply (VSS)
7. "Fmt": Bitstream Format Select (input; LOW=LJ, HIGH=RJ, OPEN=I2S)
8. "Mute": Mute Mode Select (input, internally pulled up; LOW=Mute, HIGH=Normal)
9. "SD": Serial Data (input)
10. "WS": Word Select (input)
11. "SClk": Serial Clock (input)
12. "MCLK": Master Clock (input)

Please see the datasheet on the right for more detailed information.

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