Keysight Technologies RP7900 Series, Operating And Service Manual

Page: 75 / 318

Positive, Negative, and Floating Voltages
Either positive or negative voltages with respect to ground can be obtained from the output by
grounding (or "commoning") one of the output terminals. Always use two wires to connect the load to
the output regardless of where or how the system is grounded.
l
20 V models can operate with any output terminal ± 60 VDC including output voltage from ground.
l
80 V and 160 V models can operate with any output terminal ± 240 VDC including output voltage
from ground.
l
500 V and 950 V models can operate with any output terminal ± 950 VDC including output voltage
from ground.
The RPS models are optimized for grounding the negative output terminal. Grounding
the positive terminal may result in increased current measurement noise and a
reduction in current measurement accuracy.
Additional Load Considerations - RP793xA, RP794xA
This information applies to models RP793xA and RP794xA only.
Load Inductance Limitations
EQUIPMENT DAMAGE The instrument's internal voltage clamps are susceptible to
thermal damage when the output is abruptly turned off at full load current if the lead
inductance exceeds the model-dependent
Maximum Load Inductance characteristic.
As a wire inductance reference point, a single pair of load leads typically yields between 500 nH to 1
μH per meter of paired length (round trip), depending on the gauge of wire, thickness of insulation, and
mechanical coupling of the leads. To attain greater lead lengths, wire inductance can be minimized by
paralleling additional bundled sets of load leads or using specialized low inductance wiring.
Load Capacitance and Lead Inductance Considerations in Voltage Priority Mode
For operation of the RPS units in voltage priority mode, the setup typically resembles that in the
following figure where the DUT is of a resistive or high impedance nature and may have some local
bypass capacitance near its own terminals. Remote sensing at the DUT terminals is recommended if
accurate DC voltage regulation is required.
Keysight RP7900 Series Operating and Service Guide 75
2 Installing the Instrument