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Basic operation
Probe input
The probe is electrically protected against static voltage. However, if you apply voltages above its design limits you may damage
the probe tip ampli
fi er. The limits are shown in the 0.85 V and 8.5 V range graphs on the following pages. (See Figure 1 on
page 15.) (See Figure 2 on page 16.)
Operating voltage input range
The operating voltage input range is the maximum voltage that you can apply to either of the input pins, with respect to earth
ground, without exceeding the linear input range of the ampli
fi er. A signal that is outside this range, if applied to either probe input,
can lead to an erroneous output waveform even if the differential input range is met.
Differential-Mode signal range
The differential-mode signal range is the maximum voltage difference between the (+) and (-) input pins that the probe can accept
without distorting the signal. The distortion from an input signal that is too large can result in an erroneous measurement.
Common-Mode signal range
The common-mode input voltage is the average of the voltage on the (+) and (-) input pins with respect to ground. The
common-mode voltage input range is determined by both the operating voltage input range and the amplitude of the applied
differential signal. The peak signal applied to either input pin should not exceed the operating voltage input range, so the
common-mode voltage input range is equal to the operating voltage input range reduced by one-half the amplitude of the differential
input signal. With low amplitude differential input signals, the common-mode input range is nearly equal to the operating voltage
input range. Higher amplitude differential voltages cause the common-mode input range to be reduced.
14 TDP1500 Quick Start User Manual