7 Assignment 5: MVIO - OPAMP as a Regulated Power Supply for VDDIO2

In this assignment, the AVR128DB48 Curiosity Nano will be configured to use two voltage domains VDD and VDDIO2. VDD is supplied by the CNANO voltage regulator, while VDDIO2 is supplied by OP0, which is configured as a voltage follower with the DAC as an input. The reason the DAC is not used directly to supplying VDDIO2 is that the DAC can source very little current compared to the op amp.

The Digital-to-Analog Converter (DAC) is configured to create the input voltage to OP0. Therefore, the output from the DAC will be the voltage level for VDDIO2.

The Analog-to-Digital Converter (ADC) is configured to sample VDDIO2 divided by 10. The measured VDDIO2 is streamed over to the MPLAB® Data Visualizer using the data streamer protocol.

The starting point for this assignment is the Atmel Studio Solution Assignment5 found in Assignment5.

  • Objectives
    • Understand how the AVR DB can work with two different voltage domains
    • Use the ADC to measure VDDIO2 using the internal connection
    • Plot the measured VDDIO2 using the MPLAB® Data Visualizer