TB3287
Getting Started with Multi-Voltage I/O (MVIO)
Introduction
Authors: Johan Vaarlid, Microchip Technology Inc.
The AVR
®
DB Family of microcontrollers is equipped with a configurable integrated level shifter. The Multi-Voltage I/O
(MVIO) feature allows a subset of the I/O pins to be powered by a different I/O voltage domain VDDIO2. The rest of
the I/O pins runs on VDD. Both VDD and VDDIO2 have the same voltage range. Consult the
Electrical
Characteristics
section of the data sheet for the exact voltage range. This eliminates the need of having external level
shifters for communication or control of external components running on a different voltage level. Eliminating external
logic level shifters will, in turn, reduce the BOM and free up PCB real estate.
Figure 1. Multi-Voltage I/O can Completely Replace External Logic Level Converters
VDD
1.8-5.5V
VDD
VDD
VDDIO2
GND
GND
GND
GND
GND
VDDIO2
1.8-5.5V
Microcontroller
Logic
Level
Converter
Sensor
MVIO
Sensor
Sensor
Sensor
This technical brief describes how the Multi-Voltage I/O feature works on the AVR DB Family of microcontrollers. It
covers the following use cases:
•
Polling VDDIO2 Status:
Checking if the VDDIO2 voltage is within the acceptable range by reading the Status bit.
•
Interrupt on VDDIO2 Status:
Make use of the interrupt that occurs when the Status bit changes state.
•
Measuring VDDIO2:
©
2020 Microchip Technology Inc.
Technical Brief
DS90003287A-page 1
