Test Device Makes It Easier to Measure Current Draw

Engineers who want to maximize the battery life of theircell phones and e-readers may now have an easier way to do it.

A new sourcemeasurement unit with built in "seamless ranging" technology makes it easierfor engineers to test their products and measure the amount of current they'reusing, whether it's in microamps (muA), milliamps (mA) or amps (A).

"Our devicegives research and development engineers the ability to look deep down insideand find out how much power their device is consuming, on an overall basis oron a sub-circuit level," says Kevin Cavell, product manager for Agilent Technologies, maker of the newproduct. Cavell says the new power supply can be used during the development ofmobile phones, e-readers, MP3 players, pacemakers and countless other productsthat employ batteries.

Known asthe Agilent N6781A,the new source measurement unit solves a longstanding challenge for engineersdeveloping battery-powered products. In many such products, the amount ofcurrent consumption can vary widely, from muA to A. The wide disparity (a factorof a million differences) between such current levels can cause headaches forproduct developers who must change their test set-ups and make multiplemeasurements to get the desired information. Agilent's N6781A solves thatproblem by using a power supply with three measurement ranges and an automatic"seamless measurement ranging" technology that automatically switches back andforth between them.

"Ourresearch and development engineers came up with a way of switching, so you canmeasure all three levels instantaneously and dynamically," Cavell says. "Andyou're able to make the measurements without disrupting or losing anything."

Cavell addsthat the technology is especially important for battery-powered, handhelddevices that dynamically change their current usage as they transition from fullpower to "wake-up" to "listen" modes.

"Anythingthat has a battery of 20 Watts can use this," he says. "Where battery life iscritical to the user experience, we see a market."