HFA-0003 INTERSIL [Intersil Corporation], HFA-0003 Datasheet - Page 4

• Manufacturer Part Number: HFA-0003
• Description: Ultra High Speed Comparator
• Manufacturer: INTERSIL [Intersil Corporation]

Applications Information
HFA-0003L Latch Functionality
The Latch Enable (LE) pin of the HFA-0003L controls the
function of the on chip latch. When the LE input is at an ECL
Logic 1, the latch is open (transparent) and the comparator
functions normally. When the LE input switches to a Logic 0,
the outputs are latched in unambiguous states dependant on
the current input state, providing the set-up and hold times
are met. If the latch function is not utilized, the LE input must
be connected to an ECL Logic 1 (e.g. GND).
HFA-0003L Hysteresis Functionality
To improve performance in systems with slow transition
times, and/or high noise levels, the HFA-0003L allows the
user to easily set the amount of input hysteresis. The hyste-
resis level is set by the current flowing into the HYS input;
the larger the current the larger the level of hysteresis. This
current is provided by connecting a resistor (R
the HYS pin and GND, and it is recommended that the input
current not exceed 1mA. The input current can be approxi-
mated from the following formula:
Timing Diagram
The table below gives approximate levels of hysteresis for
some values of I
If the hysteresis function isn’t used, the HYS input may be
left floating, or may be connected to V-. The HYS input
MUST NEVER BE CONNECTED directly to GND or V+, as
device damage will occur. Before inserting an HFA-0003L
into a competitor socket, the user must ensure that the cor-
responding socket pin is a true no connect (i.e. is floating).
LE
IN
I
HYS (mV)
Q
Q
H
(mA)
V
IN
H
I H
, at T
t S
0.2
1
=
COMPARE
A
GND
-------------------------------------------------
= +25
V
0.4
OD
4
–
o
(
R
C.
V-
H
t PD
) 0.7V
–
0.6
8
LATCHED
t H
0.8
13
HFA-0003, HFA-0003L
H
) between
1.0
22
3-36
t PD
t PW
L
50%
V
50%
50%
OS