PCM1808 Stereo Audio ADC Converter Module - 24-bit, 96 kHz, I2S

A module with the PCM1808 chip converts an analog stereo audio signal into a digital stream in I2S or Left-Justified format. This lets you connect a line-level signal to a microcontroller such as an ESP32 or STM32: a player output, mixer, preamplifier, or instrument. You can then record it, analyze it (FFT, visualizations), stream it over Wi-Fi/Bluetooth, or process it digitally.

Key features and benefits

• 24-bit resolution: a delta-sigma converter with 64x oversampling provides precise signal conversion.
• Good signal quality: SNR and dynamic range 99 dB (typ.), THD+N -93 dB (typ.). Clean sound with a low noise floor, more than adequate for DIY audio projects.
• Sampling from 8 kHz to 96 kHz: from speech recording to Hi-Res quality recordings.
• Built-in filters: an analog anti-aliasing filter and a digital high-pass filter that removes the DC component from the input signal.
• Master or Slave mode: the module can generate BCK and LRCK clocks itself or operate as a slave. Mode is selected with jumpers on the MD0/MD1 pins, with no register programming.
• Two data formats: 24-bit I2S or 24-bit Left-Justified, selected with the FMY pin.
• 5 V + 3.3 V power: separate voltages for the analog (5 V) and digital (3.3 V) sections. 3.3 V logic connects directly to ESP32, STM32, and Raspberry Pi Pico.
• Onboard coupling capacitors: the LIN/RIN inputs have 10 µF capacitors on the board, so a line-level signal can be applied directly.
• Compact design: dimensions 34 x 27 x 9.5 mm and 4 mounting holes.
• Wide temperature range: the PCM1808 IC operates from -40°C to +85°C.

Pinout

• LIN / RIN: Analog audio input - left / right channel (max. 3 Vp-p)
• BCK: Bit Clock
• OUT: Audio data output (DOUT)
• LRC: Left/Right channel select clock (LRCK / Word Select)
• SCK: System clock (MCLK) - 256, 384, or 512 × fs
• FMY: Data format: 24-bit I2S (FMY to GND) or Left-Justified (FMY to 3.3 V)
• MD0, MD1: Mode select: both low - Slave, other combinations - Master (512/384/256 × fs)
• +5V: Analog section power
• 3.3 / 3.3V: Digital section power
• GND: Ground

Important: the module has no onboard clock generator. A system clock (MCLK) must be supplied to the SCK pin from the microcontroller; for example, the ESP32 can generate it. Without this signal the converter will not operate.

Example applications

• Audio recorders and loggers on ESP32/STM32
• Music visualizers and spectrum analyzers (FFT, VU meters, LED effects in time with the music)
• Audio streaming over Wi-Fi/Bluetooth (e.g. wireless transmission of a mixer or turntable-with-preamp signal)
• Digital effects processors and equalizers (DSP)
• Digitizing analog sound sources

Specifications

• Chip: PCM1808
• Type: 2-channel delta-sigma ADC converter (stereo)
• Resolution: 24 bits
• Sampling rate: 8-96 kHz
• SNR / dynamic range: 99 dB (typ.)
• THD+N: -93 dB (typ.)
• Input: single-ended, max. 3 Vp-p
• Interface: I2S / Left-Justified, 24 bits, Master or Slave mode
• System clock: 256 / 384 / 512 × fs
• Power: 5 V (analog) + 3.3 V (digital)
• Chip operating temperature: -40°C to +85°C
• Dimensions: 34 x 27 x 9.5 mm
• Included: module + goldpin headers for self-soldering