Applications
DELTA CURSOR
A1 I 0.0 V j
K
—f'i-'-ir
INSTANTANEOUS
VOLTAGE LEVEL
/
VOLTAGE LEVEL
OF INTEREST
.^jQ.J,,,],,,
2 V
T
20 MS
REFERENCE CURSOR
_L_J
GROUND REFERENCE
(3832-13) 5854-11
Figure 3-1. Instantaneous voltages.
Noise
Immunity
Set the AV cursors to the upper and lower threshold limits of a digital circuit.
For example, with TTL:
1.
Superimpose the A REF cursor on the trace with input coupling at GND.
2.
Set the A cursor for a 2.0 V readout.
3. Set the A REF cursor for 1.2 V readout, the difference between the 0.8 V
lower-threshold limit and the 2.0 V upper-threshold limit.
4.
Set Input Coupling to DC and observe the relationship between the signal
and the cursors. The signal is faulty if it changes direction between cursors
or if either the high level or the low level appears between cursors.
3-2
2465B/2455B/2445B Operators