In part one of this series, Bits & Pieces introduced Atmel’s recently launched SAM4C series of products, with a spotlight on the SAM4C16 and SAM4C8. Designed for smart energy applications, these system-on-chip solutions are built around two high performance 32-bit ARM Cortex-M4 RISC processors. The devices operate at a maximum speed of 100 MHz and feature up to 2Mbyte of embedded Flash, 304 Kbytes of SRAM and on-chip cache for each core.
The dual ARM Cortex-M4 architecture facilitates the integration of various layers, including application, communications and metrology functions in a single device. It also offers options for integrated software metrology or external hardware metrology AFE (analog front end), as well as an integrated or an external power-line carrier (PLC) physical layer solution. Essentially, this is a modular approach that is sure to meet various design needs.
In part two of this series, we’ll be taking a closer look at the software and hardware metrology of the SAM4Cx. Specifically, Atmel’s software metrology library provides a comprehensive level of performance, scalability and flexibility which supports the integration of proprietary advanced metrology and signal processing algorithms.
“Atmel’s standard library enables residential, commercial, and industrial meter design up to class 0.2 accuracy, dynamic range of 3000:1, and are compliant with IEC 62052-11, 62053-22/23, ANSI C12.1, C12.20 and MID,” an Atmel engineering rep told Bits & Pieces.
“Meanwhile, software metrology front-end electronics is comprised of ATSENSE-301 and ATSENSE-101 multi-channel (up to 7) simultaneously-sampled Sigma-Delta A/D converters at 16sps, high precision voltage reference with up to 10 ppm/°C temperature stability, programmable current signal amplification, temperature sensor and SPI interface.”
Additional SAM4Cx features include:
- Poly-phase energy metering analog front end for Atmel’s MCUs and Metrology library.
- Compliant with Class 0.2 standards (ANSI C12.20-2002 and IEC 62053-22).
- Up to 7 Sigma Delta ADC measurement channels: 3 Voltages, 4 Currents, 102 dB Dynamic Range.
- Current Channels with Pre-Gain (x1, x2, x4, x8).
- Supports shunt, current transformer and Rogowsky coils.
- 3.0V to 3.6V operation, Ultra Low Power: < 22 mW typ (device fully active @ 3.3V).
- Precision voltage reference.
- Temperature drift: 50ppm typ (ATSENSE-301)and 10ppm typ (ATSENSE-301H).
- Factory measured temperature drift and die temperature sensor to perform software correction.
- 8 MHz Serial Peripheral Interface (SPI) compatible mode 1 (8-bit) for ADC data and AFE controls.
- Interrupt Output Line signaling ADCs’ end of conversion, under-run and over-run.
- Package: 32-lead TQFP, 7 x 7 x 1.4 mm.
In terms of hardware metrology (AFE), Atmel offers out-of-the-box solutions for basic metering that supports up to class 0.2 accuracy; exceeds IEC and ANSI standards and offers best-in-class temperature drift.
Additional specs include:
- A dynamic range up to 6000:1
- Optimizes performance
- Reduces OEM’s cost of manufacturing
- Great fit with SAM4L
- picoPower Technology
- Active mode @ 90μA/MHz
- Full RAM retention @1.5μA
- 4×40 Segment LCD Controller
- Hardware Crypto block