High-accuracy energy-metering IC resists tampering

The ADE7953 energy metering IC for single-phase meter configurations measures active, reactive and apparent energy along with rms voltage and current. It also provides neutral-current measurements that help designers develop tamper-proof smart meters.

The endgame is to allow designers to provide stronger protection against electricity theft, improve customer billing accuracy and reduce operating costs for utility companies supplying homes ranging from small apartments to large residences in which many appliances and electronic devices are used.

The IC incorporates three sigma-delta ADCs (analog-to-digital converters) with a high-accuracy metrology engine. Each input channel supports independent and flexible gain stages, making the ADE7953 energy metering IC suitable for use with a variety of current sensors, such as low-value shunt resistors and current transformers. Two on-chip integrators also facilitate the use of di/dt sensors for current inputs.

Key features:

• Less than 0.1 percent error for both active and reactive energy calculations over a dynamic range of 3000:1.
• For neutral current, the device offers less than 0.1 percent error active and reactive energy over a 1000:1 dynamic range. It also measures apparent energy along with rms voltage and current.
• Rms current and voltage measurements are offered with less than 0.2 percent error over a 500:1 dynamic range
• Access to on-chip meter registers via a variety of communication interfaces including SPI (serial peripheral interface), I2C or UART (universal asynchronous receiver/transmitter)
• Two configurable pulse output pins provide outputs that are proportional to active, reactive, or apparent energy, as well as rms current and voltage
• A full range of power quality information, such as overcurrent, overvoltage, peak and SAG detection are accessible via the external IRQ pin
• 3.3-V supply operation

Recommended complementary components
Recommended complementary components for the ADE7953 energy metering IC include (links go to sample distributors and include pricing) the ADP121 linear regulator, AD7814 temperature sensor, ADuM141x four-channel digital isolators, ADuM120x two-channel digital isolators, ADM2484E RS485 transceiver, ADM6320 supervisory circuit, ADP5022 buck regulator, and ADF7023 RF transceiver.

Pricing and availability
The ADE7953 is sampling now, it comes in a 28-lead LFCSP package, will be in production in January 2011, at which time it will cost $2.15 each/1,000.

Datasheet