Energy measurement chip meters power distribution units for server farms

“Smart power” usually brings to mind the smart power meters that will sit at every business or home utility box and empower the Smart Grid. There’s another layer of applications for energy measurement, however, sometimes called sub-metering, which measure power usage at the device or power distribution level. At the highest level, power is metered at the utility box when it comes into the facility - say, a data farm. It next goes into a UPS (uninterruptible power supply ) and then on to the power distribution units (PDUs) that act as smart power strips, sending the power out to 8 or as many as 64 channels, arriving ultimately at the power supplies in the servers themselves. At these huge mega-Watt installations  a variation of 1% in power efficiency is enough to win or lose business. However, without sub-metering at the PDU or power supply level, the facility can’t accurately track power consumption to better than 5% accuracy at best.

The 78M6618 power metering chip from Teridian targets data center PDUs as well as home/business smart power strips by enabling power metering, monitoring, and intelligent relay control of eight single-phase outlets simultaneously. You can control 32 or more channels by connecting multiple chips together.

Some more of the 6618’s specs: It’s a PDU power measurement and monitoring SoC with an accuracy of better than +/-0.5% over a 2000:1 dynamic range and includes self-calibration. It has a 22-bit delta-sigma ADC, 10 analog inputs, precision voltage reference and digital temperature compensation. It includes a 32-bit compute engine, an MPU core and FLASH memory.

The pricing for 1,000 units is $5.90. How does this pricing play in a world where you can buy a Kill-a-Watt meter for $25? Jay Cormier,  VP of the Energy Measurement division at Teridian, puts pricing in perspective: “If you’re looking for real-time, accurate measurement, the only way to do it today is to get an AFC (analog front end), which costs about a dollar. For 8 channels you need 8 AFEs, plus a microcontroller that adds another 50 cents. Plus, the AFEs require calibration. The 6618 comes with firmware which takes out the development time. The chip is about half the cost of the component equivalent.”

Interestingly, just last week Teridian was acquired by Maxim-IC, which is already a sginifcant player in the smart-grid communications market.  Here’s a link to the announcement (PDF.)