User`s guide

5 Operation and Connections Tutorial
108 Model N6705A User’s Guide
Measurement System Bandwidth
NOTE
The following discussion only applies when making dynamic voltage or current
measurements; not when making static (or DC) measurements.
The measurement bandwidth of the DC Power Analyzer is dependent
on the following factors:
 Whether the power module that is making the measurement has
an anti-aliasing filter
 Whether voltage or current is being measured.
 The setting of the “Compensate current measurements during
voltage transients” control
The following table documents the bandwidth for the above-
mentioned factors.
Power Module
“Compensate current
measurements” ON
(the default setting)
“Compensate current
measurements” OFF
Voltage measurements
N675xA, N676xA 10 kHz BW (– 3dB) 10 kHz BW (– 3dB)
N673xB, N674xB, N677xA 10 kHz BW (– 3dB) 25 kHz
Note
Current measurements
N6751A, N6752A 2 kHz BW (– 3dB) 10 kHz BW (– 3dB)
N6761A, N6762A 2 kHz BW (– 3dB)
2 kHz BW (– 3dB)
N6754A
10 kHz BW (– 3dB) 10 kHz BW (– 3dB)
N673xB, N674xB, N677xA 2 kHz BW (– 3dB)
25 kHz
Note
Note
Nyquist-limited to 25 kHz due to 50 kHz digitization rate.
Note that with the “Compensate current measurements” control
turned off, you will see additional current in the output current
measurement as the output capacitor charges and discharges when
changing from one voltage value to another voltage value.
The values in the shaded areas of the table will change based on the
resistance of the output load. The values specified in the table only
apply when the output load resistance is at or close to zero ohms. At
larger resistance values, errors are introduced into the measurement
due to the interaction of the output load and the power module’s
output capacitor. Use the following formula to calculate the largest
frequency that can be measured without errors.
f = maximum measurable frequency
without measurement errors
C
O
= the output capacitor value
(from the following table)
R
L
= the load resistance
C
O
=
1
2
π
f
R
L