DC analyzer gains SMU functions

As measurement units, the modules can sample voltage and current at up to 200 ksamples/s.

-- Test & Measurement World, 7/1/2010 12:00:00 AM

Agilent Technologies has added two SMU (source-measure unit) modules to its N6700 series of DC power analyzers. The N6781A simulates batteries, letting you analyze power consumption in cellphones, MP3 players, medical devices, and other battery-operated devices. The N6782A simulates rapidly changing sources and loads, letting you perform functional power testing as a device turns its subsystems on and off. Both SMUs can source or sink current while applying positive voltage, making them two-quadrant power sources.

As measurement units, the modules can sample voltage and current at up to 200 ksamples/s. They have four measurement ranges (10 µA to 3 A), and they can switch between ranges without causing "glitches" in power delivery. To do that, the modules use a set of shunt resistors that are all in series with the source output. This arrangement differs from the traditional configuration of having multiple resistors in parallel, with switches connecting one at a time in series with the source's output. The digitizer measures the voltage across any one of the resistors while the others are shorted. Each resistor has a voltage regulator across it that controls the source unit's output, keeping it smooth as ranges change. Eliminating the glitches removes power disruptions that affect the device under test.

Agilent has also developed the 14585A software that lets you control up to four N6705 mainframes (16 power supplies). The software enhances the instrument's data-analysis capabilities and lets you create complex power waveforms.

Prices: N6781A—$5300; N6782A—$4230; N6705B mainframe—$6900; 14585 software license—$1240.

Agilent Technologies, www.agilent.com.