MCP4725 DAC

• VIN to board 5V
• GND to board GND
• SCL to board SCL with 2K resistor
• SDA to board SDA with 2K resistor
• VOUT to left mono jack tip

QT Py RP2040

• GND to left mono jack sleeve
• GND to right mono jack sleeve
• A1 to right mono jack tip

The 2K resistors for SCL and SDA keep the incoming logic level at 3.3V, rather than 5V.

Why Not Use a STEMMA QT Cable?

The DAC is using the QT Py RP2040's 5V output for power so that the 1V/oct signals have a range of 0 to 5V. If you do not need a range of 5V, then you can use a STEMMA QT cable to power the DAC with 3.3V and make the GND and I2C connections.