Source-measure units from Keysight target battery-driven product power optimisation

February 24, 2015 // By Graham Prophet
Keysight Technologies has added two source/measure units (SMUs), that feature dynamic current measurement, to its N6700 Series modular power systems – the N6785A two-quadrant SMU for battery drain analysis and the N6786A two-quadrant SMU for functional test. Both SMUs provide power output up to 80W.

These SMUs expand the N6780A Series SMU family by offering up to four times more power than the previous models. The new models offer sourcing, measurement and analysis to help engineers deliver the best possible battery life in their devices. The N6785A and N6786A SMUs allow engineers to test devices that require current up to 8A, such as tablets, large smartphones (known as phablets), police/military handheld radios and components of these devices.

The N6780A Series SMUs eliminate the challenges of measuring dynamic currents with a feature called seamless measurement ranging. With seamless measurement ranging, engineers can precisely measure dynamic currents without any glitches or disruptions to the measurement. As the current drawn by the device under test (DUT) changes, the SMU automatically detects the change and switches to the current measurement range that will return the most precise measurement.

When combined with the SMU’s built-in 18-bit digitiser, seamless measurement ranging enables effective vertical resolution of (in the region of) 28-bits. This capability lets users visualise current drain from nano-Amps to Amps in one pass. All data needed is presented in a single picture, which helps users unlock insights to deliver exceptional battery life.

N6780 Series SMUs offer;

- Stable, glitch-free sourcing and sinking (charge/electronic load), just like a battery

- Programmable output resistance mimics the battery’s internal resistance

- Engineers can characterise a device’s off-, sleep- and transmit-mode current in one pass

- Engineers can perform battery rundown tests and characterise how a device performs with an actual battery with the SMU’s ammeter (zero-burden current shunt) mode

- The built-in digitizer measures and logs voltage, current and power approximately every 5 µsec (a 200 kHz measurement rate)

14585A software provides scope, data logger and CCDF functionality to see and analyse short- and long-term power usage; the Keysight 14585A control and analysis software for the N6705 DC power analyser enhances the user experience of the N6705 mainframe by offering advanced functionality