HP 33120A, User Manual

Page: 53 / 118

DC Offset Voltage
At power-on, the dc offset is set to 0 volts. You can set the offset to a
positive or negative number with the restrictions shown below. If the
specified offset voltage is not valid, the function generator will
automatically adjust it to the maximum dc voltage allowed with the
present amplitude. (V
max is either 10 volts for a high impedance
termination or 5 volts for a 50 ohm termination; V pp is the output
amplitude in volts peak-to-peak.)
From the front panel, “
MAX VALUE
” is displayed and the offset
is adjusted. From the remote interface, a -221, “Settings conflict” error is
generated and the offset is adjusted.
•
DC Offset and Output Termination : The offset voltage is automatically
adjusted (and no error is generated) if you change the output
termination. For example, if you set the offset to 100 mVdc and then
change the termination from 50 ohms to “high impedance”, the
displayed offset will
double to 200 mVdc. If you change from “high
impedance” to 50 ohms, the displayed offset will drop in half.
See “Output Termination” on page 65 for more information.
•
For dc volts , the output level is actually controlled by setting the
offset voltage. You can set the dc voltage to any value between
±
5 Vdc
into 50 ohms or
±
10 Vdc into an open circuit.
To select
dc volts
from the front panel, press
Offset
and
hold it down
for more than 2 seconds
.

V
offset

+
V
pp
2
≤
V
max
and

V
offset

≤
2
x
V
pp
Chapter 3 Features and Functions
Output Configuration
62