Texas Instruments Inc. last week unveiled what it claims is the first single-chip mixed-signal controller designed for electronic energy meters.
The MSP430FE42X family targets an accelerating shift by energy meter makers away from mechanical systems to electronic designs, which allow remote monitoring and require fewer components.
TI's new chips are part of a series of 16-bit application-specific MCUs the Dallas-based company plans to introduce this year. Additional products will be geared for use in glucose and water meters, among other devices, for which ultralow power consumption and sensing accuracy are critical.
TI said the chip family reduces the bill of materials for energy meters by incorporating five of the main system components in a single IC, comprising a high-performance analog front end, a 16-bit microcontroller, flash memory, real-time clock, and LCD driver.
The MCU block contains an embedded signal processor (ESP) to handle metrology calculations, and a second RISC processor that can be used for remote management functions--such as automated meter reading, smartcard prepayment, and multiple-rate billing--via an RF, Bluetooth, or powerline interface.
Remote management is driving growth in the deployment of electronic energy meters, primarily in Asia, where utility companies are scrambling to keep up with rapid housing development, according to May Ann Choo, marketing manager for e-meter products at TI.
It is catching on to a lesser extent in the United States, and TI is engaged with one major U.S. meter maker, Choo said.
This year, TI estimates that roughly 45 million electronic energy meters will ship worldwide out of a total of 100 million units overall. While some new deployments contain a mixture of electronic and mechanical components, by 2010 all energy meters manufactured will be electronic, Choo said.
To offload metrology calculations from the main CPU, TI has embedded the ESP, which offers 0.1% accuracy. Supporting the ESP are three independent 16-bit sigma-delta A/D converters operating at an oversampled rate of 1MHz, three programmable gain amplifiers, a temperature sensor, and a precision voltage reference.
The chip operates from 1.8 to 3.6V, with power consumption of 1.1µA in standby with real-time clock active, and 2.5mA in 3V operation.
Standard peripherals include a watchdog timer, 128-segment LCD driver, brownout protection, supply voltage supervisor, three-channel pulsewidth modulation timer, serial communication interface, and serial onboard programming. A 32Kbyte block of flash memory allows meters to be updated in the field.
MSP430FE42X parts are sampling, with production planned for year's end. Pricing starts at $2.95 in 100,000s..