Process instruments include the electronics required to measure process variables, such as temperature, pressure, level and flow, using a variety of sensors and methods. Power consumption in active mode is critical for these products, as most field instruments are powered though a 4-20mA current loop interface, which strongly limits the available power budget for the electronics. Process instruments must often be able to operate in hazardous areas, and cannot buffer energy.

Atmel® has become a leading supplier of microcontroller for the manufacturers of industrial process instruments.

Features and Benefits

  • Atmel 32-bit microcontrollers can operate down to 1.62V and achieve sub 1mW/DMIPS power consumption figures.
  • Process instruments often operate the microcontroller at low frequencies to reduce power consumption. Atmel has optimized the Flash read accesses in these conditions.
  • The Atmel AVR 32-bit microcontroller and the Atmel ARM® Cortex™-M3 processor-based SAM3 family provide modern and efficient RISC architectures, supporting more complex signals.
  • Embedded DSP functionalities (MAC, saturating arithmetic) and FPU, along with middleware libraries to support them, considerably simplify signal conditioning.
  • Complex signal algorithms, field bus or industrial Ethernet support, functional safety test routines, and multi-language menus, require increasingly large embedded Flash support. Atmel offers 32-bit microcontrollers with embedded Flash up to 512KB.
  • Atmel microcontrollers integrate dedicated hardware mechanisms to support the implementation of the IEC61508 safety standard. Learn more about Atmel microcontroller safety functions.
  • Wireless communication is attractive for industrial sites with instruments dispersed over a large area. The Atmel wireless microcontroller product line provides the required hardware platform to build products compatible with the popular Wireless HART protocol. The Atmel best-in-class RF properties help increase range and make RF links more robust, yet highly efficient.
  • The Atmel CryptoAuthentication™ family of hardware security products provides easy-to-implement, cost-effective and low standby power solutions for secure communication to/from process instruments.
Process Instruments Diagram

The Atmel SAM3, SAM7 and the AVR UC3 32-bit families deliver a unique combination of low power and excellent signal processing capabilities.

  • Low power consumption
  • Efficient signal processing (DSP and FPU)
  • Wide Flash size availability
  • Sensor element and field bus connection
  • Safety functions according to IEC61508
  • Capacitive touch
  • Wireless microcontroller

Atmel Products

MicrocontrollerTouchSecure AuthenticationRF MicrocontrollerMemory
AVR UC3 B Series

ARM-based Solutions: SAM3S/7S

Buttons, Sliders and Wheels

QTouch library

maXTouch™ Touchscreen controller
Single-chip (Microcontroller and Transceiver)


ZigBit Modules
CryptoMemory: Secure EEPROM


Overview of the Atmel Safety Features

 FeaturesAtmel SAM3 FamilyAtmel AVR XMEGA FamilyAtmel AVR UC3 Family
Code IntegrityFlash with write protectionSelectable flash regionsApplication and boot sectionSelectable flash regions
Dual BankYes (SAM3U)  
Flash ChecksumCRC unit (SAM3S)CRC UnitSoftware
WatchdogRunning from an internal RC oscillatorYesYesYes
Lock functionLocked after first writeLocked per fuseKey protected
Window modeYesYesYes (AVR UC3)
Software RunawayMemory Protection UnitYesNoYes
Lock function for the IO registerYes, using the MPUYesYes, using the MPU
Lock function for the Clock ConfigurationYesYesYes
Lock Event System ConfigurationN/AYesYes
Clock FailureStart-up from internal RC oscillatorYesYesYes
Main clock failure detectionYes (SAM3S)YesYes
Automatic switch to the internal RCYes (SAM3S)YesYes

Atmel AVR and ARM Comparison

CPU AVR Family ARM-based Solutions
Product Family AVR XMEGA 8/16-bit microcontroller AVR UC3 32-bit microcontroller SAM3 microcontroller SAM9 MPU
CPU Feature Best-in-class 8/16-bit RISC hardware multiplier 32-bit RISC with DSP support (Single cycle MAC, saturation) Cortex-M3 with MPU ARM926-EJ
Active Mode 0.5 mW/MHz < 1mW/MHz 1 mW/MHz 0.125mW/MHz
Wait Mode 0.55µA 70µA 4.6µA 8mA
RTC Mode 0.55µA 1.6µA 1.6µA 9µA
Power Down < 100nA 100nA 100nA  
Field Instrument Temperature, Low-end Pressure & Flow Temperature, Pressure, Flow, Level, Analysis Temperature, Pressure, Flow, Level, Analysis Level, Flow, Liquid Analysis

Reference Designs

[ + ] Wireless Thermostat with SAM4LC Reference Design

[ + ] QTouch Robustness Reference Design

[ + ] Wireless SoC with RFMDs RF6505/6575/6555

[ + ] ISM Band PCB Antenna Reference Design

[ + ] Wireless E-Paper Display Reference Design

Learn more about the Atmel solution Application Notes, Devices, and Tools and Software.