Single-chip energy metering solution from Analog devices

ADI's new ADE7100 and ADE7500 energy meter SoC families include devices with intelligent battery modes that allow the meters to maintain the time, sense temperature changes, run the LCD (liquid crystal display) read-out, and perform other critical system functions, while using at least 40 percent less power than competitive solutions. Based on Analog Devices' field-proven ADE energy measurement core, which has been designed into more than 175 million energy meters worldwide, the highly integrated SoC devices perform functions previously requiring as many as six discrete ICs and further extend ADI's portfolio of industry-leading energy metering solutions.

"For electricity meter designers who require a better solution to the growing demand for feature- rich, highly reliable LCD energy meters, the ADE7100 and ADE7500 families provide an accurate, low-power and intelligently integrated solution for single-phase energy meters," said Lu Han Xi, chief engineer at energy meter manufacturer Linyang Electronics in China. "We look to Analog Devices' for leadership based on its legacy of designing metering solutions that have excellent accuracy and reliability."

The ADE7100 and ADE7500 energy meter families combine Analog Devices' proven energy measurement core with a microprocessor, on-chip flash memory, LCD driver, real-time clock (RTC) and intelligent battery management circuitry. The result is a high-quality, cost-effective solution that is less susceptible to system failures and enables advanced services like remote meter-reading, time-of-use billing, which requires power companies to measure energy consumption according to hourly use, and load shedding, which is the act of cutting off the electric current on certain lines when demand outstrips supply.

"Analog Devices' leadership position gives it a unique perspective on the needs of our energy metering customers - both in terms of the technology that gets them to market faster and at lower cost, as well as the next-generation features that keep them competitive," said Pat O'Doherty, product line director, Precision Signal Processing Group, Analog Devices. "The industry shipped over 100 million energy meters last year, and as that number continues to climb, we believe the ADE7100 and ADE7500 families will meet the growing requirements for efficient, highly integrated solutions."

The highly integrated ADE7100 and ADE7500 families provide an SoC solution for energy meters with LCD-displays. The devices combine ADI's metering core, derived from the ADE7755, with intelligent
battery management circuitry consisting of an internal battery switch and a stand-alone state machine. With a low battery-mode current consumption of 1.2 microamps, the devices reduce power use by at least 40 percent in battery mode compared to competitive solutions, while still allowing the meters to maintain critical functions--such as monitoring temperature and main supply voltage--during power outages.

The installation of energy meters with LCD displays continues to accelerate globally. To address this trend, the ADE7100 and ADE7500 families integrate an LCD driver that meets industrial temperature specifications for all outdoor climate conditions. On-chip charge-pumps controlled by a digital-to-analogue converter (DAC) allow designers to easily adjust LCD contrast by setting the drive voltage
up to 5.4V with a power supply of 3.3V, which ensures the display is clearly visible even as temperature ranges fluctuate between -40 degrees C to 85 degrees C.

Analog Devices' energy metering core includes active, reactive and apparent energy calculations, as well as voltage and current rms (root-mean-square) measurements. Several power supervisory features, such as SAG detection, peak and zero crossing, are built into the core to simplify energy meter design. The devices' microprocessor includes a single-cycle 8052 core, an RTC with full battery backup and a choice of a UART (universal asynchronous receiver-transmitter), SPI (serial peripheral interface) or I2C interface. The ADE7100 family of products feature a second current input for tamper detection.

Four products in the ADE7100 (ADE7166, ADE7169) and ADE7500 (ADE7566, ADE7569) families are sampling now with full production scheduled for February 2007. The devices are available in 64-lead LQFPs (low-profile quad flat packages) and are priced under $3.00 per unit in 1,000-piece quantities.