TI Introduces MSP430 Microcontroller Family for Electronic Energy Metering

DALLAS. (July 31, 2003) -Texas Instruments introduced today the industry's first system-on-chip microcontroller unit (MCU) for electronic energy meters (e-meter). By combining an industry-standard ultra-low-power Flash MCU with an integrated high-performance analog front-end (AFE) on a single-chip, the mixed-signal integration of the new MSP430FE42x family of products reduces the total system chip count by eighty percent, improving performance and reliability, while reducing cost and time to market when compared to first generation electronic solutions.

Reduced Component Count
Systems using the MSP430FE42x family do not require external crystals, EEPROM, LCD driver, external real time clock or a 5V power supply. The reduced component count and the devices' inherent failsafe features increase overall reliability.

"Using the MSP430FE42x, designers can quickly develop hassle-free, high-performance energy meters," said Mark Buccini, MSP430 product line marketing manager for TI. "While performance is clearly increased, the automatic metrology function can cut critical time-to-market and cost in half."

In addition, this new family of single-chip MCUs eliminates the need for expensive long-lead-time custom multi-chip AFEs. As a Flash memory MCU-based system, the same hardware can be used for many platforms with feature or country-specific changes made only in software. Because the Flash is in-system programmable, it is even possible to update a deployed meter remotely.

Embedded Signal Processor Increases Meter Accuracy
To provide the highest possible performance and simplify system design, the device integrates an embedded signal processor (ESP), ideal for single phase e-meters, plus the following key features to perform the energy metrology functions:

• Three independent 16-bit sigma-delta analog-to-digital converters operating at an oversampled rate of 1MHz
• Three programmable gain amplifiers
• Temperature sensor
• Precision voltage reference

The converted line voltage and current signals are digitally processed, providing:

• energy and line period measurement
• negative power flow indication
• peak voltage and current
• phase and line-to-neutral current comparisons for tamper detection

With precise phase matching between current and voltage channels, the ESP performs the necessary calculations to supply accurate active energy, apparent energy, RMS voltage, current and waveform samples. The ESP provides a 0.1 percent accurate energy measurement over a dynamic current range of 1000 to 1, greatly surpassing the 1 percent accuracy common in typical mechanical meters. Having the ESP completely manage critical energy calculations enables the designer to utilize the freed-up central processor unit (CPU) functions for differentiated meter features such as display and AMR.

Ultra Low Power Performance
A flexible clock system with five low-power modes enables unmatched ultra-low-power performance and complete operation using only a single 32.768kHz watch crystal. The low-frequency watch crystal, in combination with the integrated user-programmable, digitally-controlled oscillator, precisely meets system power and performance requirements.

The MSP430FE42x operates at 3V with the CPU and ESP active at only 2.5mA. In a power outage the device can operate in a standby mode with a typical current consumption of 1.1uA with the real-time-clock active.

The family also includes standard MSP430 peripherals such as:

• Enhanced watchdog timer
• Integrated LCD driver for up to 128 segments
• Brownout protection
• Supply voltage supervisor
• Three channel pulse width modulation (PWM) timer
• Serial communication interface (Asynchronous UART or Synchronous SPI)
• Onboard Serial Programming of the onchip Flash memory (no external programming voltage required)

Development Tools Support
The MSP430FE42x family is fully compatible with the existing $99 MSP-FET430P410 JTAG emulation toolkit. The tool supports real-time in-system application development, accessing the Flash device's embedded emulation capability. The tool comes complete with a JTAG interface, target board and a complete integrated development environment (IDE) including a debugger, assembler/linker and 4kB C-Compiler.

Pricing and Availability
The MSP430FE42x family offers:

• 8kB, 16kB or 32kB on-chip Flash memory
• 256B to 1kB RAM
• 64-pin quad flat pad (QFP) package
• and is available for preproduction and engineering evaluation now
• full production planned for late 2003

The 8kB MSP430FE423 is priced at $2.95 per unit in 100,000-piece quantities.

About Texas Instruments
Texas Instruments Incorporated provides innovative DSP and analog technologies to meet our customers' real world signal processing requirements. In addition to Semiconductor, the company's businesses include Sensors & Controls, and Educational & Productivity Solutions. TI is headquartered in Dallas, Texas, and has manufacturing, design or sales operations in more than 25 countries.