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POWERFUL AVR® ANALOG PERIPHERALS Issue #1: The Zero Cross Detector on AVR DA

The recently released AVR DA family of microcontrollers from Microchip heralds the next generation of AVR MCUs. It is the first device to be jointly developed using design expertise and IP from both of Microchip's R&D centres located at Chandler (Arizona) and Trondheim (Norway).

All new AVR devices will have an extensive focus on providing powerful and highly capable core independent analog features and functions going forward. This will add an extra dimension to the already well-trusted AVR platform that the design community has come to know and appreciate, thereby allowing for a greater degree of creativity to their applications. The AVR DA family pair the latest digital peripherals with a robust Intelligent analog portfolio to create a device that not only excels as a standalone processor but also as a companion MCU in designs that demand precision. It is suited for industrial control, home appliance, automotive and Internet of Things (IoT) applications.

WHAT IS A ZERO CROSS DETECTOR (ZCD)?

The ZCD is an intelligent peripheral that detects when an Alternating Current (AC) signal crosses through the ground potential. It is very useful when monitoring AC waveforms for purposes such as TRIAC dimming, AC period measurement and minimizing EMI caused by switching transients. The AVR DA depending on the package selected, can have up to 3 Zero Cross Detectors.

The on-chip ZCD peripheral can take the signal directly from the AC main with only a current-limiting resistor (and/or capacitor in some cases) in series with the input. The output is a simple digital level that toggles from active low to high when the signal crosses from negative to positive or vice versa. This output signal can be used to trigger other peripherals internally, or output to a GPIO pin externally, or simply act as an interrupt. Having an integrated ZCD negates the need to build an external circuit with passive components which could lead to higher power consumption and BOM costs. This dedicated onboard peripheral is very easy to configure and also acts a buffer preventing direct current injection into the substrate, that may damage the MCU.

GETTING TO KNOW THE AVR DA ZERO CROSS DETECTOR

Watch this video to learn how to configure and use the ZCD in conjunction with the on-board Digital-to-Analog Converter (DAC) utilising Atmel Studio (IDE), Atmel START (Code Configurator) and the AVR128DA48 Curiosity Nano Evaluation Kit.

AVR128DA48 CURIOSITY NANO EVALUATION KIT RS (204-2690)

The AVR128DA48 Curiosity Nano Evaluation Kit offers complete support for your next design. The platform is equipped with an On-board debugger, Virtual serial port (CDC) and two logic analyser channels (Debug GPIO). Easy board identification through Atmel START.

200131-MCU8-PHOTO-DM164151-Angle-Pins-Transparent_e87c16291976d164363f4398ebe8031132eb60b4.png

CURIOSITY NANO BASEBOARD for Mikrobus Click Modules RS (193-6490)

The Curiosity Nano Base for Click boards™ evaluation kit is a hardware extension platform to ease the connection between Curiosity Nano kits and extension boards like the mikroBUS Click modules and Xplained Pro extension boards. 200221-MCU8-PHOTO-AC164162-Angle-Transparent_40ff79e8f50ae6b2271fccc66b8a7f6e6fdd9332.png

THE MICROCHIP CORE INDEPENDENT PERIPHERAL PHILOSOPHY

>The Zero Cross Detector is one of many highly effective peripherals available throughout the AVR range and embodies Microchip's Core Independent Peripheral (CIP) philosophy. This approach is possible through the well known AVR Event System and is an integral part of core independent operation. CIPs are designed to enable deterministic closed-loop control with zero intervention from the MCU's Central Processing Unit (CPU).

Watch the following video to learn about these easy-to-configure peripherals:

Benefits of Core Independent Peripherals:

REDUCE DEVELOPMENT TIME - REDUCE CODE OVERHEAD - DETERMINISTIC - INCREASED POWER SAVINGS

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November 2020:

POWERFUL AVR ANALOG PERIPHERALS SERIES ISSUE #2AVR DB MVIO (MULTI-VOLTAGE I/O)

Senior Product Marketing Manager at Microchip Norway AS. Responsible for Business Development Activity of the PIC and AVR range of microcontrollers throughout EMEA.
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