Tektronix TriMode TDP7700 Series Technical Reference page 19

TDP7700 Series TriMode Probes Technical Reference
Using any of the TekFlex solder-in tips, probe connections are made to the two
complementary signals (the A signal and the B signal) and a ground reference.
From this single DUT connection, the internal electronic switching control of the
TriMode probe allows any one of the four probe input modes to be selected at a
time. The TriMode probe inputs are routed to an ASIC (application-specific
integrated circuit) inside the probe to a set of four independent input amplifiers
that perform the following signal calculations:
■ A – B (for differential signal measurement)
■ A – GND (for A input single-ended measurement)
■ B – GND (for B input single-ended measurement)
■ [A+B]/2 - GND (for common mode measurement)
NOTE. In the B – GND Mode, the negative polarity B input is not inverted.
The four input amplifiers are multiplexed together and only the selected input
mode function is sent to the connected oscilloscope. The following figure shows
a conceptual view of the TriMode probe input structure, where the C input
provides the probe ground reference and is connected to the probe tip ground
interconnect using the probe's cable coaxial shields.
Figure 6: TriMode input structure
Theory of operation
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