LT1720CS8#PBF Linear Technology, LT1720CS8#PBF Datasheet - Page 23
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LT1720CS8#PBF
Manufacturer Part Number
LT1720CS8#PBF
Description
IC COMP R-RINOUT DUAL 8-SOIC
Manufacturer
Linear Technology
Series
UltraFast™r
Type
General Purposer
Datasheet
1.LT1720CS8PBF.pdf
(28 pages)
Specifications of LT1720CS8#PBF
Number Of Elements
2
Output Type
CMOS, Rail-to-Rail, TTL
Voltage - Supply
2.7 V ~ 6 V
Mounting Type
Surface Mount
Package / Case
8-SOIC (0.154", 3.90mm Width)
Comparator Type
High Speed
No. Of Comparators
2
Response Time
4.5ns
Ic Output Type
CMOS, TTL
Supply Current
4mA
Supply Voltage Range
2.7V To 6V
Amplifier Case Style
SOIC
No. Of Pins
8
Rohs Compliant
Yes
Output Compatibility
CMOS, TTL
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
APPLICATIONS INFORMATION
Coincidence Detector
High speed comparators are especially suited for interfac-
ing pulse-output transducers, such as particle detectors,
to logic circuitry. The matched delays of a monolithic dual
are well suited for those cases where the coincidence of
two pulses needs to be detected. The circuit of Figure 19
is a coincidence detector that uses an LT1720 and discrete
components as a fast AND gate.
The reference level is set to 1V, an arbitrary threshold. Only
when both input signals exceed this will a coincidence
be detected. The Schottky diodes from the comparator
outputs to the base of the MRF-501 form the AND gate,
while the other two Schottkys provide for fast turn-off.
COINCIDENCE COMPARATORS
51Ω
51Ω
5V
Figure 19. A 3ns Coincidence Detector
0.1μF
3.9k
1k
–
+
+
–
1/2 LT1720
1/2 LT1720
A logic AND gate could instead be used, but would add
considerably more delay than the 300ps contributed by
this discrete stage.
This circuit can detect coincident pulses as narrow as 3ns.
For narrower pulses, the output will degrade gracefully,
responding, but with narrow pulses that don’t rise all the
way to “high” before starting to fall. The decision delay is
4.5ns with input signals 50mV or more above the refer-
ence level. This circuit creates a TTL compatible output
but it can typically drive CMOS as well.
For a more detailed description of the operation of this
circuit, see Application Note 75, pages 10 and 11.
4 1N5711
300ps AND GATE
5V
300Ω
5V
MRF501
300Ω
17201 F19
OUTPUT
GROUND
CASE LEAD
LT1720/LT1721
23
17201fc