Chapter 2: Probing and Selecting the Sampling Mode

Probing the Device Under Test

 

You can order mating connectors separately using the Agilent part

 

number:

 

1253-3620 (or Samtec #ASP-65067-01)

 

You can order support shrouds separately using the Agilent part

 

numbers:

 

16760-02302 for PC board thicknesses up to 0.062 in.

 

16760-02303 for PC board thicknesses up to 0.120 in.

Electrical

Data threshold reference inputs

Considerations

The E5378A single-ended probe has two inputs for threshold reference

 

 

voltages for the data inputs. One input is for the even pod and the

 

other is for the odd pod. The threshold inputs (pins 87 and 88) may be

 

either:

 

Connected to a DC threshold reference voltage. In this case, the logic

 

analyzer will use the threshold reference voltage to determine when the

 

signal is high or low.

 

Or:

 

Grounded or left unconnected. In this case, you need to set the logic

 

threshold voltage in the user interface.

 

The advantages of supplying a threshold voltage via the threshold input

 

on the probe are:

 

• A threshold voltage supplied from the device under test will typically track

 

changes in supply voltage, temperature, etc.

 

• A threshold voltage supplied from the device under test is typically the

 

same threshold that the device's logic uses to evaluate the signals.

 

Therefore, the data captured by the logic analyzer will be the same as the

 

data interpreted by the device under test.

 

Clock Input

 

The clock input on the E5378A probe can be a differential signal or a

 

single-ended signal.

 

If the clock input is a differential signal, select the "differential" option

 

in the clock threshold user interface.

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Agilent Technologies 16760A Numbers, Either, On the probe are, Single-ended signal, Clock threshold user interface