Operation With Fixed Voltage Sources In Series; Adjustment Under Actual Lead And Load Conditions - HP E1328A User Manual

Operation with
If a fixed voltage must be placed in series with the load, connect the voltage
source to the V+ lead for the most accurate output. An example of this type
Fixed Voltage
of application is shown in Figure 4-4. The emitter follower configuration
Sources in Series
increases the total available output current.
Figure 4-4. Emitter Follower Configuration
If the fixed voltage source is placed in the V- lead, a small error will occur
in the output voltage. An output error of approximately 0.05% of the
voltage between V- and S- occurs due to the 51Ω protection resistor in
series with the S- terminal. This error does not occur if the voltage between
V- and S- is due solely to lead resistance, provided that an electronic
adjustment has been performed with the same load and lead configuration as
under actual operating conditions.
Adjustment Under
Whenever possible, perform electronic adjustments with the D/A Converter
connected to the leads and load to be used in operation. An electronic
Actual Lead and
adjustment performed under actual operating conditions provides the best
Load Conditions
output accuracy.
If an electronic adjustment is performed with a different V- lead resistance than
that encountered under actual operating conditions, small errors will occur in
the output voltage due to the effect of the 51Ω protection resistor mentioned in
the preceding section, "Operation with Fixed Voltage Sources in Series".
34 Understanding the HP E1328A Chapter 4