T-DSP Mic Array Module

KiCad PCB design for a MEMS microphone array module, part of the T-DSP ecosystem.

Overview

A combined beamforming + stereo capture microphone array built around two TAC5212 codec modules:

• TAC5212 #1: 4 PDM microphones (2 per data line via SELECT pin)
• TAC5212 #2: 2 PDM microphones + 2 Knowles SPM0687LR5H-1 analog MEMS microphones on differential inputs

The 6 PDM mics are arranged in a circular array (50mm diameter, ~26mm spacing) for beamforming. The 2 analog MEMS mics are positioned as a stereo pair in the center for low-noise stereo capture (70dB SNR, 130dB AOP).

Interface

• Teensy 4.1 footprint for standalone operation
• T-DSP expansion header for integration with the Desktop Pro or other mainboards

Key Components

• PDM Microphones: SPH0645LM4H (x6, circular array)
• Analog MEMS Microphones: Knowles SPM0687LR5H-1 (x2, center stereo pair)
• Codec: TAC5212 modules (x2)

Known Issues

PDM microphone footprints are not verified. A previous spin may have indicated that the pins are swapped on the PDM mic footprints. Check the footprints against the datasheet before fabrication.

Notes

The TAC5212 codec modules can be swapped with the pin-compatible ADC-only version of the chip if you only need microphone inputs. Since both TAC5212 modules have stereo outputs, you can also add two headphone outputs or other analog outputs to the board.

Project Structure

t-dsp_mic_array_module.kicad_pro   # KiCad project file
t-dsp_mic_array_module.kicad_sch   # Schematic
t-dsp_mic_array_module.kicad_pcb   # PCB layout
lib_sch/                           # Project symbol libraries
lib_fp/                            # Project footprint libraries
3d_models/                         # 3D models for components
lib_dl/                            # Downloaded component libraries
lib_docs/                          # Component datasheets

Requirements

• KiCad 9.0+

License

See repository for license details.