Datasheet
Each DC power module in the Keysight
N6705 DC power analyzer has a fully
integrated digitizer to capture the actual
voltage-versus-time and current-versus-
time being sourced from the DC output
into the DUT. The digitized data appears
on the large color display just like an
oscilloscope. Because this oscilloscope
function is built in, it is possible to
make current measurements without
current sense resistors, current shunts,
or current probes. This greatly reduces
measurement setup complexity and
provides for accurate and fully specified,
calibrated measurements. The accuracy
of the measurements in oscilloscope
mode is based on the type of power
module installed (basic, high-performance
autoranging, precision, and SMU). You
can find this information in the Keysight
N6700 Modular Power System Family
Specifications Guide under “Oscilloscope
Measurement Accuracy.”*
The N6760 and N6780 SMU series
of power modules offer simultaneous
digitizing of output voltage and output
current, such that you can view a voltage
trace and a current trace at the same time
on the oscilloscope display. For all other
module types, you can select to view
either a voltage trace or a current trace on
the oscilloscope display.
Oscilloscope: Scope View
The table below shows the relationship
between the number of scope traces, the
sample rate, and the buffer size available
for each trace. As shown, the digitizer
can run at up to 200 kHz with up to 256
k samples per trace (512 k samples with
SCPI commands). With an effective
measurement bandwidth of up to 30 kHz,
this oscilloscope function is perfectly
matched to capture time varying events
on the DC output, such as peak current
demand, dropouts, rise times and other
DC transients and disturbances.
The measurement buffer size can be set to
between 1 k and 256 k points. Whatever
buffer size is selected, its available points
must be divided by the total number of
traces being measured.
Figure 4. In scope view, voltage and
current traces are displayed. In this
picture, the DC current flowing into the
DUT is clearly visible as a time-varying
waveform.
Power module type Number of traces
(1 trace = V or I)
Fastest sample rate Maximum buffer
size available per
trace
One N6780 SMU 1 trace 5.12 µs
(~ 200 kHz)
256 k points
Any power module 1 or 2 traces 10.24 µs
(~ 100 kHz)
128 k points
Any power module 3 or 4 traces 20.48 µs
(~ 50 kHz)
64 k points
Note that the measurement window is
determined by multiplying the selected
buffer size by the sample rate. For a
measurement window of 60 seconds for
example, with a buffer size set to 256 k
points, the fastest sample rate available
to you will be 234 microseconds. If the
buffer size is set to 64 k points, the
fastest available sample rate will be 937
microseconds.
The oscilloscope can be triggered on
either voltage or current levels. Because
the Keysight N6705 DC power analyzer
is an integrated instrument, the oscil-
loscope can also be easily configured
to trigger on the start of an arbitrary
waveform or to trigger when the DC
power output is enabled. For example, to
make an inrush current measurement on
your DUT, you can set the oscilloscope
to trigger on the DC output’s on/off key,
set the trigger mode to single shot, and
then turn on the DC output. This will
immediately capture the current flowing
out of the DC module into the DUT and
give a picture of the inrush current of
the DUT. This integrated functionality
is not available when using a collection
of separate test instruments on the test
bench and is an example of how the DC
power analyzer reduces setup time and
complexity.
* Complete specications are available at http://literature.cdn.keysight.com/litweb/pdf/N6700-90001.pdf
6 | Keysight | N6700 Modular Power System Family - Data Sheet