Hardware

Electronics & PCB

Connecting the amp to other hardware

Logic Levels

• The Teensy uses 3.3V digital logic levels whereas the MAX98389 uses 1.8V.
• The i2s signals go through a Texas Instruments TXS0108EPWR chip to convert to/form 1.8V and 3.3V.
• The i2c signals (SDA and SCL) each go through a FET transistor circuit for level shifting as these are open-drain signals.

Power

• The Teensy, which generates the 3.3V supply, is powered over USB.
• The 1.8V supply is generated from the 3.3V supply and therefore also powered by USB.
• The MAX98389 requires two supplies - one for digital logic (1.8V) and one for powering the amplifier output (5-10V). This allows the amp to be configured via i2c without the external power supply.

External power

Transducer

3D Printed Parts