max9687cse Maxim Integrated Products, Inc., max9687cse Datasheet - Page 4

• Manufacturer Part Number: max9687cse
• Description: Dual, Ultra-fast Ecl-output Comparator
• Manufacturer: Maxim Integrated Products, Inc.

Dual, Ultra-Fast ECL-Output Comparator
minimum slew-rate requirements. The tendency of the
part to oscillate is a function of the layout and source
impedance of the circuit employed. Both poor layout
and larger source impedance will increase the mini-
mum slew-rate specification.
In many applications, the addition of regenerative feed-
back will assist the input signal through the linear
region, which will lower the minimum slew-rate require-
ment considerably. For example, with the addition of
positive feedback components Rf = 1k
Cf = 10pF, the minimum slew-rate requirement can be
reduced by a factor of four.
The timing diagram (Figure 3) illustrates the series of
events that complete the compare function, under
worst-case conditions.
The top line of the diagram illustrates two latch-enable
(LE) pulses; each pulse is high for the compare func-
tion and low for the latch function. The first pulse
demonstrates the compare function in which part of the
input action takes place during the compare mode.
The second pulse demonstrates a compare-function
interval during which there is no change in the input.
The leading edge of the input signal (illustrated as a
large-amplitude, small-overdrive pulse) switches the
comparator after time interval t
are similar in timing. The input signal must occur at time
t
must be maintained for time t
the output is no longer affected by the input status until
the latch is again strobed. A minimum latch pulse width
of t
output transitions occur after a time t
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
4 ___________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 [phone]
© 1993 Maxim Integrated Products
Figure 3. Timing Diagram
s
____________________Timing Diagram
before the latch falling edge and, to be acquired,
pw
(E) is needed for the strobe operation, and the
DIFFERENTIAL
VOLTAGE
ENABLE
LATCH
INPUT
Q
Q
LATCH
V
IN
h
after the edge. After t
pd
. Outputs Q and
pd
COMPARE
(E).
Printed USA
t
s
V
OD
t h
t
pd
and
–
Q
h
–
,
V
V
V
t
t
t
t
t
t
t
pd+
pd-
pd+
pd-
pw
s
h
OS
IN
OD
(E)
(E) Latch-Enable to Output Low Delay—The propa-
(E) Latch-Enable to Output High Delay—The propa-
is a registered trademark of Maxim Integrated Products.
t
pw
Input Offset Voltage—The voltage required
between the input terminals to obtain 0V differ-
ential at the output.
Input Voltage Pulse Amplitude
Input Voltage Overdrive
Input to Output High Delay—The propagation
delay measured from the time the input signal
crosses the input offset voltage to the 50% point
of an output low-to-high transition.
Input to Output Low Delay—The propagation
delay measured from the time the input signal
crosses the input offset voltage to the 50% point
of an output high-to-low transition.
gation delay measured from the 50% point of the
latch-enable signal low-to-high transition to the
50% point of an output low-to-high transition.
gation delay measured from the 50% point of the
latch-enable signal low-to-high transition to the
50% point of an output high-to-low transition.
mum time the latch-enable signal must be high
to acquire and hold an input signal.
Minimum Setup Time—The minimum time before
the negative transition of the latch-enable pulse
that an input signal must be present to be
acquired and held at the outputs.
Minimum Hold Time—The minimum time after
the negative transition of the latch-enable signal
that an input signal must remain unchanged to
be acquired and held at the outputs.
Minimum Latch-Enable Pulse Width—The mini-
(E)
t
pd
(E)
Definition of Terms
50%
V
50%
50%
OS