Tektronix 2445A - Data Hold Time Checks; Minimum Clock Pulse Width Checks

3. Check Data Hold Time.
a. For each test setup described in Table 4-12: Vary
the
pulse duration of pulse generator # 2 until the first
edge of the channel 2 signal falls about 10
ns after the
trigger edge of the channel 1 signal.
2. CHECK-A stable signal is displayed on chan-
nel 3.
3. Vary the pulse duration of pulse generator # 2,
moving the first edge of the channel 2 signal to
the left until
channel 3 no longer displays a
stable signal.
4. Push the at button.
5. Turn the a REF OR DL Y POS control to align
the delta reference cursor with the first
edge of
the channel 2 signal.
6. Turn the a control to align the delta cursor with
the first
edge of the channel 1 signal.
7. CHECK-Reading is> 4 ns.
8. Push the at button.
Table 4-12
Data Hold Time Checks
Polarity
Word
A
Recognizer TRIGGER
Pulse Generator
Word SLOPE
# 1
#2
Definition
+ +
!-1-FFFF
-
+
-
!-0-0000
-
-
-
l-0-0000
+
-
+
l-1-FFFF
+
Performance Check-2445A/2455A Service
4. Check Minimum Clock Pulse Width.
a. Set pulse generator # 1 to produce a 5-ns positive
pulse every 1
µS.
b. Push the NB MENU button to select A TRIGGER
MODE.
c. Push the upper TRIGGER MODE button to reinitial-
ize the auto-trigger level.
d. Push the NB MENU button.
e. For each test setup described in Table 4-13:
1. If there is not a stable signal displayed on chan-
nel 3 ( < 2.5 V amplitude), vary (increase) the
pulse duration of pulse generator
# 1 until chan-
nel 3 displays a stable signal.
2. Push the at button.
3. Turn the a REF OR DL Y POS control to align
the delta reference cursor with the leading
edge
of the channel 1 pulse.
4. Turn the a control to align the delta cursor with
the trailing edge of the channel 1 pulse.
5. CHECK-Reading is < = 20 ns.
6. Push the at button.
Table 4-13
Minimum Clock
Pulse Width Checks
Polarity Word
A
Recognizer
TRIGGER
Pulse Generator
Word SLOPE
#1 #2 Definition
+ +
l-X-XXXX
+
-
+
!-X-XXXX
-
4-41