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External TDM DACs

Phil Schatzmann edited this page Apr 2, 2024 · 29 revisions

Regular I2S DACs support only 2 channels. With TDM we can get much more channels. However you need to use a microcontroller that supports TDM!

This is not yet supported by the AudioTools, but I am working on it. Please let me know if you want to help me...

CS42448

The CS42448 CODEC from Cirrus Logic provides six multi-bit analog-to-digital and eight multi-bit digital-to-analog delta-sigma converters.The DAC is configured with the help of I2C.

1 2 3 4 5
NC SCL SDA NC NC
GND NC NC 5V NC

         Master Control

The SPI pins are provided via the Master Control. Unfortunatly the pins are not indicated, so I am documenting them here. SCL is on the colum 2 and SDAa on colum 3 of the first row, if you position the board so that the master control is on the top.

image

AD1938

The AD1938 is a high performance, single-chip codec from Analog Devices, that provides four analog-to-digital converters (ADCs) with input and eight digital-to-analog converters (DACs) with single-ended output. An SPI port is included, allowing a microcontroller to adjust volume and many other parameters.

Configuration

Unfortunately this board does not make the SPI pins available, but you can configure the device with the help of the SIP3:

image

To use DTM at 48000, just remove the bridge.

Pinout

image