HP 1660CS, User Manual

Page: 128 / 347

Probe and Pod Grounding
Each pod is grounded by a long, black, pod ground lead. You can connect the
ground lead directly to a ground pin on your target system or use a grabber.
To connect the ground lead to grounded pins on your target system, you
must use 0.63-mm (0.025-in) square pins, or use round pins with a diameter
of 0.66 mm (0.026 in) to 0.84 mm (0.033 in). The pod ground lead must
always be used.
Each probe can be individually grounded with a short black extension lead
that connects to the probe tip socket. You can then use a grabber or the
grounded pins on your target system in the same way you connect the data
lines. For extra confidence in your measurements, grounding every third or
fourth probe is recommended.
When probing signals with rise and fall times of 1 ns or less, grounding each
probe lead with the 2-inch ground lead is recommended. In addition, always
use the probe ground on a clock probe.
Probe Leads
The probe leads consists of one 12-inch twisted-pair cable, one ground tap,
and one grabber. The probe lead, which connects to the target system, has an
integrated RC network with an input impedance of 100 k
Ω
in parallel with
approximately 8 pF, and all in series with 250
Ω
. The probe lead has a
two-pin connector on one end that snaps into the probe housing.
Probe ground lead
Probe ground
Probe lead connector
Probing
General-purpose probing system description
7-9