This is electronics circuit note on Audio DAC like PCM1789, where they can be used and how to use in embedded system projects.
Audio DAC are used to convert audio inside microcontrollers or microprocessors which is stored in binary audio format or processed in real time in binary format to raw audio signal using DAC(Digital to Analog Converter, often sigma delta type).
Example usage would be a microphone that collects audio signal from surrounding and uses ESP32 or Raspberry Pi and similar microcontroller or microcontroller boards that supports I2S(Inter-IC Sound) communication and then store the audio after ADC(Analog to Digital Conversion) in SD card or internal flash memory (NVRAM), or External PSRAM / SPI RAM. The 8 bit Arduino will not work but some 32-bit Arduino board will work. This stored audio can be then sent out to first audio DAC chip like PCM1789 and then from PCM1789 like audio DAC to external audio amplifier plus speaker for replay of the audio.
A note on the PCM1789 Audio DAC is below.
PCM1789PWR is a high-performance, single-chip 24-bit, 192kHz Stereo Audio Digital-to-Analog Converter (DAC) manufactured by Texas Instruments. It is designed for applications requiring high-fidelity audio reconstruction from serial digital PCM streams.
Key Technical Specifications
Audio Resolution & Sample Rate: Supports 24-bit audio data with sampling rates up to 192kHz.
Audio Input Formats: Accepts standard serial digital audio formats including $I^2S$, Left-Justified, and Right-Justified PCM data.
Dynamic Range & Distortion:
Dynamic Range: $113\text{ dB}$ (typical)
THD+N (Total Harmonic Distortion + Noise): $-95\text{ dB}$ (0.0018% typical)
Output Type: Single-ended voltage outputs ($2.0\text{ V}_{\text{RMS}}$ full-scale output).
Power Supply: Operates from a single $+5\text{V}$ analog power supply ($V_{CC}$) and $+3.3\text{V}$ digital power supply ($V_{DD}$).
Control Interface: Hardware control mode (pins set mode/de-emphasis) or software control via $I^2C$ or SPI modes depending on the system configuration.
Package & Pinout Details
Package Code (PWR): TSSOP-24 package provided on tape and reel (
R).Built-in Functions:
System clock auto-detection ($256f_s, 384f_s, 512f_s, 768f_s$).
Digital attenuation and soft-mute control.
On-chip anti-aliasing low-pass filter and analog voltage reference.
Typical Applications
PC Audio Systems: Sound cards, external USB DAC units, and high-resolution line-out interfaces.
AV Receivers & Set-Top Boxes: Processing digital audio signals into clean line-level analog outputs.
Embedded Systems: Paired with microcontrollers or DSPs (like ESP32 or STM32) over $I^2S$ to stream high-quality analog audio into an external power amplifier stage.
