Tool/software:
Hello E2E Team,
We have a new design which requires the synchronized sampling of 16 PDM microphones.
In our design the sample rate of each Mic should be 48Khz with a sample depth of 16bit
Please advise on the way to sync the sampling from 4xPCMD3140 devices each connected to 4 microphones.
Is it recommended to connect each PCMD3140 device to a separate I2S bus or is it recommended to multiplex them on the same I2S bus?
Best Regards
Lev
Hi,
For using multiple PCMD3140 devices, we can multiplex the TDM/I2S bus. In order to do so, the TDM/I2S slots in which the devices transmit the data need to be configured independently through I2C register control. Considering the PCMD3140 device has a single I2C address, we would need separate I2C buses for each device.
In case of interfacing 16 microphones at 48 kHz, we can use PCMD3180, which can interface up to 8 PDM channels. Two of these devices can be interfaced to a common I2C bus by configuring different I2C addresses through the ADDR0/ADDR1 pins. The below links are for the PCMD3180 datasheet, along with the application note describing how to use a shared TDM/I2S buses with multiple devices.
PCMD3180 Octal-Channel, PDM Input to TDM or I2S Output Converter datasheet (ti.com)
Thanks and Regards,
Lakshmi Narasimhan
