Hoping to convert the electronic energy metering market from an electromechanical to electronic technology, Texas Instruments has unveiled a single-chip microcontroller that may cut time-to-market and cost in half. The device trims part counts by about 80%, which should also improve reliability.
The U.S. has about 110 million electric meters, says the Automatic Meter Reading Association International (AMRA, www.amra-intl.org). Of those, only about 19 million offer automated meter reading, and many of those are electromechanical, according to a 2001 study by Scott Reports.
TI's MSP430FE42x line of system-on-chip microcontrollers incorporates many of the functions needed for metering, speeding design over products that use discrete parts or more than one custom chip. Electric energy is measured to 0.1% accuracy over a dynamic current range of 1,000:1, far more precise than the 1% accuracyof most mechanical meters.
The IC includes up to 32 kbytes of flash memory and an analog front end that includes three 16-bit A/D converters and three programmable gain amplifiers. It draws little power, operating at 3V and drawing only 2.5 mA when both the CPU and embedded signal processor are active. Standby power consumption drops to 1.1 microA even when the real-time clock is working.
Brownout protection, a supply voltage supervisor and a serial communication interface are on the chip. The 8-kbyte flash version sells for $4.85 in 1,000-piece orders with production shipments set for later this year.