MCUs For Automated Meter Reading Use Very Little Power

Texas Instruments’ highly integrated MSP430F47x4 reduces power consumption to extend battery life while cutting components count. With standby power consumption as low as 1.5 μA, the 16-MHz MSP430F47x4 ultra-low power microcontrollers extend battery life to over 12 years in one- and multiphase automated meter-reading applications. The F47x4 series MCUs feature several low-power modes allowing the meter to “sleep” with almost no power-drain between readings. An extremely fast wake-up function brings the device to full clock speed within 6 μs. Combined with a fast shutdown capability, this “instant-on” wakeup minimizes time spent in active mode. The result is fewer costly service calls for battery replacement.

The device includes up to four individual 16-bit sigma-delta analog-to-digital converters, a 32-by-32-bit hardware multiplier, a 160-segment LCD driver with contrast control, up to 60 kbytes of flash memory, and a real-time clock. This high level of integration produces a five-to-one reduction in system components. TI’s utility metering portfolio also includes devices for water- and gas-metering, as well as power-line communications and RF interfaces for automated meter reading. The previously available MSP430FE42xx series of devices includes an embedded signal-processing unit that integrates the metering function—including current and voltage measurement and power calculations—for faster system development and a reduced bill of materials.