After connecting the adapter to the flex cable, use the retainer to provide a secure connection to the flex cable to minimize
movement or to attach the adapter to the hand’s free tripod.
For stacking more than one adapter, use the linkage adapter accessories to secure the P77C292MM adapters together.
Probe input architecture
Input architecture
TDP7700 Series probes feature a new probe architecture that addresses the need for high frequency response with
decreased probe loading for high-speed, low power applications such as MIPI® and LPDDR. High performance probes with
multi-GHz bandwidth have evolved in recent years, starting from traditional designs with metal pin tips attached to a probe
head amplifier located at the end of a coaxial cable. As the probe bandwidth extended to 10 GHz and above, probe designs
migrated to connectorized amplifier input structures that supported a variety of high frequency passive probe tips, including
solderable tip designs. These probe tips typically provide a passive input attenuator network at the probe tip followed by a
long cable attached to the probe amplifier connection socket. Although these passive tip, probe designs enable good, high
frequency performance, they show higher probe loading in the frequency band below 1 GHz than earlier traditional designs
with an amplifier closer to the probe tip. A probe with this higher loading characteristic below 1 GHz has problems when
taking measurements of signals such as MIPI that can be switched to an unterminated, high impedance mode for low power
operation. The TDP7700 Series probe solves this loading problem by introducing an active probe tip design with a tiny
buffer amplifier located near the tip inputs. By locating an amplifier with a high impedance attenuator network at the probe
tip inputs, the probe tip parasitic capacitance can be kept much lower than passive cable tip designs, thus reducing probe
loading in the low power signaling frequency band used by serial data standards such as MIPI.
The following figure shows a simplified diagram of the TekFlex active probe tip architecture.
Figure 4: TDP7700 Series TriMode probe input architecture
The TekFlex active probe tip has two inputs, A_IN and B_IN, which can, depending on the tip design, support TriMode
measurements. With a TriMode tip, such as a TekFlex solder-in tip, it is possible to make differential, single-ended A, single-
ended B, and common-mode measurements, all from a single soldered differential signal connection to a DUT. The
soldered wire connections between the two probe tip input signal vias and DUT differential signal nodes should be kept as
short as possible (as should the ground via connections if single-ended measurements will be made). The A and B input
signals on the probe tip pass to a matched pair of damping resistors, Rd, that isolate the probe connection to the DUT. The
Theory of operation
TDP7700 Series TriMode™ Probes Technical Reference
4
