4470-ADA Adafruit MCP4728 Quad DAC with EEPROM - STEMMA QT / Qwiic

Adafruit MCP4728 Quad DAC with EEPROM - STEMMA QT / Qwiic

If you've ever said to yourself, "Gee, I wish I had four 12-bit DACs that came in a single package with the ability to save their settings to an EEPROM", well I have good news. The MCP4728 is the answer to your wishes! Within its little package, the MCP4728 has four 12-bit DACs for whatever voltage setting needs you may have. In addition, it has the ability to store the settings for the DACs to an internal EEPROM. Once saved to the internal non-volatile memory, the settings will be loaded by default when the DAC powers up. All over I2C!

To take things even further, the MCP4728 lets you chose between two sources for your reference voltage: the input voltage that you use to power it on the VCC pin, or an internal 2.048V reference voltage. If you use the internal reference voltage (Vref in DAC speak) you can choose between 1X or 2X gain for the output, allowing your voltages to range from 0V to 2.048 or 0V to 4.096V as your application requires.

By default you'll use the input voltage as your Vref, allowing you to scale the voltages from 0V-3.3V or 5V depending on your input voltage. Or, use the 2.048V Vref for ~3.3V usage, and the 4.096 Vref for ~5V usage.

The breakout for the MCP4728 is populated with the required support circuitry to use it with your microcontroller of choice or Blinka-supported computer. The SparkFun Qwiic compatible STEMMA QT JST SH connectors ease the process of connecting the MCP4728 to your project and allows you to easily share an I2C bus with other STEMMA QT, Qwiic, Grove, or other compatible sensors. QT Cable is not included, but we have a variety in the shop.

Our drivers, wiring diagrams, and example code for Arduino, CircuitPython and Python make it easy to get started so you can get rolling with your project instead of figuring out how to wire things or get the code working.

Technical Details

Technical specifications

• 12-Bit Voltage Output DAC with Four Buffered Outputs
• On-Board Nonvolatile Memory (EEPROM) for DAC Codes and I2C™ Address Bits
• Internal or External Voltage Reference Selection
• Output Voltage Range:
  - Using Internal VREF (2.048V):
  0.000V to 2.048V with Gain Setting = 1
  0.000V to 4.096V with Gain Setting = 2
  - Using External VREF (VDD): 0.000V to VDD
• ±0.2 Least Significant Bit (LSB) Differential Nonlinearity (DNL) (typical)
• Fast Settling Time: 6 μs (typical)
• Single-Supply Operation: 2.7V to 5.5V
• Default I2C address 0x60 or 0x64

Revision History:

As of Aug 1, 2022 - due to intense chip shortages, we may make this board with the MCP4728 (default address 0x60) or MCP4728A4 (default address 0x64). This PCB was updated to not include the I2C address on the back silkscreen. Note that the address is re-programmable in EEPROM.