Low-power digital isolators

November 14, 2013 // By Graham Prophet
The ADuM144x family of iCoupler digital isolators reduces power by a claimed factor of 1,000 compared to optocouplers to improve energy efficiency, and comes in the industry’s smallest package.

Analog Devices presents the ADuM144x family as the industry’s lowest-power digital isolators. Based on ADI’s iCoupler digital isolation technology, they can use as little as 1 μW, delivering power levels over 1,000 times lower than optocouplers and competing digital isolators. At these levels the ADuM144x family is suited for industrial and instrumentation systems such as 4-20 mA current loops, remote sensors and green systems that demand high energy efficiency or depend on limited power sources.

The ADuM144x are in a quad-channel data isolator available in three different channel configurations with a one-minute isolation safety rating of 2.5 kV rms. They have an operating voltage range of 2.25 to 3.6V, further reducing power constraints and providing the lowest isolator operating voltage on the market. Quiescent power supply current at 2.5V is less than 5 μA per channel, and power supply current at 2 Mbps is less than 380 μA per channel. A power saving mode can reduce current levels to as little as 0.1 μA per channel, resulting in 1 μW of total power for the entire isolator. In addition to the significant power savings, the ADuM144x is available in a 16-lead QSOP package, making it the smallest quad-channel digital isolators with a 2.5-kV rms isolation rating.

The ADuM144x family employs the same iCoupler chip-scale transformer technology used in ADI’s full line of safety isolation products. In 4 x 5 mm, 16-lead QSOP (AduM144xARQZ) the devices cost $1.98; in 7.2 x 5.3 mm, 20-lead SSOP (AduM144xARSZ) they will cost $2.48 (from January 2014) (both @ 1000). An evaluation board costs $49.00.

Analog Devices; www.analog.com/ADuM144x A video is at; http://analog.com/ADuM144xvideo