HP 1660CS, User Manual

Page: 129 / 347

Grabbers
The grabbers have a small hook that fits around the IC pins and component
leads. The grabbers have been designed to fit on adjacent IC pins on either
through-hole or surface-mount components with lead spacing greater than or
equal to 0.050 inches.
Probe Cable
The probe cable contains 18 signal lines, 17 chassis ground lines and two
power lines for preprocessor use. The cables are woven together into a flat
ribbon that is 4.5 feet long. The probe cable connects the logic analyzer to
the pods, termination adapter, or preprocessor. Each cable is capable of
carrying 0.33 amps for preprocessor power.
C A U T I O N
DO NOT exceed 0.33 amps per cable, or the cable will be damaged.
Preprocessor power is protected by a current limiting circuit. If the current
limiting circuit is activated, the fault condition must be removed. After the
fault condition is removed, the circuit will reset in one minute.
Minimum Signal Amplitude
Any signal line you intend to probe with the logic analyzer probes must
supply a minimum voltage swing of 500 mV to the probe tip. If you measure
signal lines with a voltage swing of less than 500 mV, you may not obtain a
reliable measurement. Because the minimum input overdrive is the greater
of 250 mV or 30% of input amplitude, be sure to correctly set the pod
threshold in the Analyzer Format menu.
Pod Thresholds
Logic analyzer pods have two preset thresholds and a user-definable pod
threshold. The two preset thresholds are ECL (
−
1.3 V) and TTL (+1.5 V).
The user-definable threshold can be set anywhere between
−
6.0 volts and
+6.0 volts in 0.05 volt increments.
All pod thresholds are set independently.
Probing
General-purpose probing system description
7-10