ICs Make Meter Designs Easier, Energy Theft Harder

Oct 1, 2007 12:00 PM
By David Morrison, Editor, Power Electronics Technology

The AS8268 incorporates all the required functional blocks for single-phase metering including a precision energy measurement front end, an 8-bit microcontroller, 32 kbytes of on-chip flash memory, a real-time clock, 96-segment LCD driver, 12 programmable multipurpose inputs/outputs for all possible customer-specified interfaces and display requirements, as well as an on-chip temperature sensor.

Fig. 4. The AS8268 single-phase, anti-tamper LCD energy-metering IC from austriamicrosystems offers an integrated system-on-chip solution for LCD display meters and features secure program and data through its on-chip high-performance flash memory. (click image to see full-sized figure)

“The extremely reliable austriamicrosystems flash memory technology provided on-chip ensures program and data retention performance never before available to the metering industry in system-on-chip ICs,” says Matjaz Novak, marketing director of industry and medical for austriamicrosystems. “The flash memory has been designed and verified to operate over an extended operating temperature range of –40ºC to 125ºC.”

The AS8268 offers the option of using an external EEPROM of 2 kbytes to 32 kbytes for data retention, in conjunction with the fully programmable industry-standard 8-bit 8051-compatible microcontroller and 32 kbytes of on-chip flash memory. Two UARTs provide for external communication. A programmable energy LED pulse output can be displayed through one of the multipurpose input/outputs.

This precision output along with an on-chip pulse counter allows for the option of fast automatic digital calibration. An on-chip ±1.4-ppm real-time clock/calendar with two alarm registers and battery backup is available for complex tariff applications, with the option of added precision through the on-chip temperature sensor.

Active energy, mains voltage and mains current are calculated directly within the on-chip digital signal processor. Reactive power and apparent power can also be calculated by user-configurable application software. The AS8268 is available in a LQFP-64 pin package and is pin compatible with the currently available AS8218 and AS8228. Samples of the AS8268 are available.

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© 2007 Penton Media, Inc.