Operating Voltage Window - Tektronix TriMode TDP7700 Series Technical Reference

Theory of operation
Voltage window. The operating voltage window defines the input signal voltage

Operating voltage window

range within which probe measurements can be made with good fidelity. The
operating voltage window limits is a function of input dynamic range, offset and,
in the case of the P77C292MM adapter, V . In the figures below, the grey area
term
demonstrates the range of signals that can be measured by a tip. The smaller
green box illustrates the dynamic range considering specific offset levels. The
dynamic range square can be moved around within the operating window by
adjusting the A and B offset settings.
Figure 10: Operating voltage window (TekFlex solder-in tips)
The A operating voltage window range of ±5.25 V is shown on the vertical axis
and the B operating voltage window range of ±5.25 V is shown on the horizontal
axis. The dynamic range is also shown on the figure as the smaller green square.
The TekFlex solder tip single-ended dynamic range for both the A and B inputs is
2.5 V . Differentially, the solder tip dynamic range is 5 V .
p-p p-p
Because there are several step gain values available within the TDP7700 Series
Probe Amplifier, the actual size of the dynamic range square depends upon the
oscilloscope vertical scale factor setting. The vertical scale factor determines the
required probe amplifier step gain setting, which is automatically set to the
proper value under the oscilloscope control.
The dynamic range square is set to its full-size 2.5 V setting when the vertical
p-p
scale factor is set to large enough V/div settings that a 2.5 V signal can be fully
p-p
displayed on the oscilloscope. As the vertical scale factor is set to lower V/div
settings, the probe amplifier step gain threshold will eventually be reached and
the step gain value will be increased by one step. In C and D mode, only
common-mode and differential offset adjustments are possible. For active tips,
this is represented by the one-dimensional figures below.
Figure 11: Operating voltage window (diferential mode, flex tip)
TDP7700 Series TriMode Probes Technical Reference 17