Eecl High-Speed D-Binary 1820-0557; Dual Nand Schmitt Triggers 1820-0537 - HP 5340A Operating And Service Manual

4-41. Dual NAND Schmitt Triggers 1820-0537

4-42. This IC (Figure 4-18) functions as a four-input NAND gate with Schmitt trigger action.
The Schmitt action gives different input threshold levels for positive- and negative-going
signals. This difference between the threshold levels is called hysteresis and is typically 800
millivolts. Built in temperature compensation is included to ensure high stability of the threshold
levels and hysteresis. These characteristics allow triggering on slow input ramps and ensure
clean, jitter-free outputs.
Figure 4-18. Dual NAND Schmitt Triggers 1820-0537
NC

4-43. EECL High-speed D-Binary 1820-0557

4-44. The 1820-0557 is a 350 MHz binary counter using the dual rank master-slave design. The
truth table for synchronous or asynchronous operation is shown in Figure 4-19.
Figure 4-19. EECL High-speed D-Binary 1820-0557
2D 2C NC
positive logic: Y
=
No internal connection.
-
SYNCHRONOUS:
X
ASYNCHRONOUS:
H = OV Nominal
N O T E :
must transfer low n o t later than
low t o ensure latching i n set condition.
Theory of Operation
2A 2 Y
Clocks o n positive transition
of C 1 or C 2 (C1
Sets or resets o n positive transition
Normal set operation
Normal reset operation
Set dominant
L
=
C2) must be low during set operation or
t
Model 5340A
C2)
L
or H
4-13