04 | Keysight | Probing Solutions for Logic Analyzers - Data Sheet
Reliable Connections Ensure Accuracy
Signal frequency content drives probing solutions
– Impedance
High input impedance ensures
minimum intrusion on your circuit.
Although many probes might be
acceptable for lower frequencies,
capacitive loading becomes
significant at higher frequencies. The
Keysight probing products perform
over a wide frequency spectrum.
Faster clock rates demand tighter timing tolerances, such as setup and hold
specifications. Systems with faster clock rates usually have shorter rise and fall times.
Signals with shorter transition times have more high frequency content and are more
susceptible to high frequency analog problems such as cross talk, reflections, ground
bounce, noise and emissions. Susceptibility of a system to analog problems relates to
the transition times of the signals, not the clock rate. A system with slow transition times
cannot have high clock rates. However, it is possible for a system with slower clock rates
to have signals with very fast transition times.
– Ruggedness
General-purpose probing solutions provide the analog bandwidth required to run
each logic analyzer module at its maximum clock rate. The high input impedance of
these probes, especially at high frequencies, presents a minimal load to most systems.
Systems that are operating with little margin should be designed with consideration for
both the system components and the input impedance of the probing solution being
used during debug. Input impedance specifications or equivalent load diagrams can be
found for each of the probing solutions described in this document.
Probes with quality mechanical
design provide solid electrical
connections. Intermittent open
circuits would only add one more
variable to your debugging equation.
Keysight probes are mechanically
designed to relieve strain and ensure
rugged, reliable connection.
– Immunity to Noise
Electromagnetic noise can corrupt
data captured by the logic analyzer.
Keysight probing solutions are
designed for a high immunity to
transient noise.
Which Logic Analyzer?
For logic analyzers with 160-pin front panel connector, use probes identified in
this document as “Direct-connect probes.”
For logic analyzers with cables that use a 3M-style connector with two rows of
20 pins on 0.1-inch centers, as illustrated in Figure 1.1, use probes identified in
this document as “for analyzers with 40-pin pod connectors.”
– Performance
Keysight logic analyzers have
front-end circuitry that supports the
state and timing specifications of
the analyzer. This circuitry, together
with the Keysight probing solutions
described in this document, will
accurately capture the target signals
at the specified clock rates.
For logic analyzers with cables that use a 90-pin, high-density connector as
illustrated in Figure 1.2, use probes identified in this document as “for analyzers
with 90-pin pod connectors.”
90-pin pod connector (pages 10 to 36)
16950B, 16951B
40-pin pod connector (pages 47 to 70)
16911A
U4164A, U4154A/B, and 16962A
16910A
16800 Series benchtop analyzers
Other considerations
Physical connection compatibility
between various Keysight probes may
allow you to mix and match a variety
of probes and accessories. However, a
probe accessory designed for slower
clock speeds will not deliver high-speed
target performance simply because it
is used with a higher speed analyzer
module. Also, the serial connection of
multiple probe leads and/or accessories
will degrade signal integrity.
Direct connect probe/cables
(pages 37 to 39)
U4164A
U4154A/B, 16850 Series
Figure 1.1. 40-pin pod connector
Figure 1.2. 90-pin pod connector