LT8440

The EVAL-LT8440-AZ evaluation circuit features the LT8440 used in a load power port of an intrinsically safe field device. It can regulate and limit the power drawn by the port according to the Ethernet Advanced Physical Layer (Ethernet-APL) standard. The EVAL-LT8440-AZ is designed with three LT8440s in series to meet the triple redundancy requirement of intrinsic safety Ex ia for class A field devices, but it can be configured to work with a lower LT8440 count. See the Redundancy of LT8440 section for more details.

The evaluation circuit is also equipped with filters and protection components to meet the Ethernet-APL and intrinsic safety standards, including IEC60079-11 and IEC60079-47 standards. Communication signal integrity is well preserved on this evaluation circuit, allowing seamless link up between 10BASE-T1L devices.

The EVAL-LT8440-AZ board is designed to operate from 9V to 17.5V input voltage. Across the input voltage range, the LT8440 draws current in parallel with the load up to the 500mW minimum guaranteed for Class A load power ports in compliance with Advanced Physical Layer (APL) standards. In case of load circuit failures, the evaluation board also limits input power below 650mW. The LT8440 shunts current even at no load to ensure at least 20mA input current during normal operation, which is required by APL specification for signal integrity.

Design files for this circuit board are available at Product Evaluation Boards and Kits | Design Center | Analog Devices.

• DIN B compatible design allows easy prototyping of Ethernet-APL field devices
• Designed and certified for Intrinsic safety (I.S.), Ex ia IIC Ga
• Tested for Ethernet-APL compliance (IEEE 802.3cg-2019)
• Functional Safety ready (SIL-2) with hardware diagnostics and FMEDA documentation
• Highly efficient solution maximizing power available to the field device
• Extensive security features: built-in security for hardware root-of-trust, data confidentiality and integrity, and secure communications
• Open-source software stack
• Supports PROFINET, Ethernet-IP, MQTT
• The kit includes 3 boards, I.S. certified boards and a third one to enable access to the RISC-V JTAG debugger.
• Programmers for ARM and RISC-V included

AD-EthernetAPLDevice-SL is a complete Ethernet-APL field platform designed for prototyping intelligent, secure, and connected field devices.

The platform is certified for intrinsic safety (Ex ia IIC Ga) and tested for Ethernet-APL compliance. It is also functional safety ready (SIL2), featuring the MAX42500 voltage monitor, with integrated windowing watchdog, the MAX6613 temperature sensor, the ADFS7124-4 sigma-delta ADC functional safety approved to SC3, and complete FMEDA documentation.

The system integrates the MAX32690—a dual-core ARM Cortex-M4 with FPU and a RISC-V co-processor. This MCU is paired with external RAM (512 Mb) and Flash (64 Mb) to meet the demands of high-performance applications.

A 10 Mbps single-pair Ethernet link, enabled by the ADIN1110 10BASE-T1L MAC/PHY, supports remote data acquisition and system configuration.

The platform is APL-compliant and powered via Single-Pair Power over Ethernet (SPoE), supporting an input voltage range of 9 V to 15 V. It is recommended to use the DEMO-ADIN1100D2Z as both the power source and media converter for Ethernet signals (10BASE-T1L ↔ 10BASE-T).

The kit includes a third, non-intrinsically safe board that provides access to the RISC-V JTAG interface for debugging.

An open-source software stack and supporting collateral are included, enabling seamless experience from evaluation and prototyping to production firmware and application development. The stack includes drivers and example applications for a wide range of ADCs, DACs, sensors, and other industrial components, accelerating development.

The platform supports Zephyr (with an available board definition) and is also supported in Code Fusion Studio.

An example PROFINET stack software application is available to enable easy evaluation and system prototyping (myanalog.com registration required).

APPLICATIONS

• Process automation
• Factory automation
• Field instruments
• Internet of Things