LT1394
7ns, Low Power,
Single Supply, Ground-Sensing
Comparator
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FEATURES
DESCRIPTIO
UltraFastTM: 7ns
The LT®1394 is an UltraFast(7ns) comparator with comple-
mentary outputs and latch. The input common mode range
extends from 1.5V below the positive supply down to the
negative supply rail. Like the LT1016, LT1116 and LT1671,
this comparator has complementary outputs designed to
interface directly to TTL or CMOS logic. The LT1394 may
operate from either a single 5V supply or dual ±5V supplies.
Low offset voltage specifications and high gain allow the
LT1394 to be used in precision applications.
■
■
Low Power: 6mA
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Low Offset Voltage: 0.8mV
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Operates Off Single 5V or Dual ±5V Supplies
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Input Common Mode Extends to Negative Supply
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No Minimum Input Slew Rate Requirement
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Complementary TTL Outputs
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Inputs Can Exceed Supplies without Phase Reversal
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Pin Compatible with LT1016, LT1116 and LT1671
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Output Latch Capability
Available in 8-Lead MSOP and SO Packages
The LT1394 is designed for improved speed and stability for
a wide range of operating conditions. The output stage
provides active drive in both directions for maximum speed
intoTTL,CMOSorpassiveloadswithminimalcross-conduc-
tion current. Unlike other fast comparators, the LT1394
remains stable even for slow transitions through the active
region,whicheliminatestheneedtospecifyaminimuminput
slew rate.
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APPLICATIO S
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High Speed A/D Converters
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Zero-Crossing Detectors
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Current Sense for Switching Regulators
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Extended Range V/F Coverters
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Fast Pulse Height/Width Discriminators
The LT1394 has an internal, TTL/CMOS compatible latch for
retaining data at the outputs. The latch holds data as long as
the LATCH pin is held high. Device parameters such as gain,
offsetandnegativepowersupplycurrentarenotsignificantly
affected by variations in negative supply voltage.
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High Speed Triggers
Line Receivers
High Speed Sampling Circuits
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, LTC and LT are registered trademarks of Linear Technology Corporation.
UltraFast is a trademark of Linear Technology Corporation.
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TYPICAL APPLICATIO
45MHz Single Supply Adaptive Trigger
Propagation Delay vs
Input Overdrive
5V
2k
12
10
8
T
V
V
= 25°C
STEP
= ±5V
6
A
3
1
5
= 100mV
Q1
Q2
S
5V
3M
4
2
5V
500pF
+
–
0.005µF
t
+
–
A1
LT1227
PDLH
6
t
A2
LT1006
PDHL
0.005µF
3M
Q1, Q2, Q3, Q4 = CA3096 ARRAY:
4
TIE SUBSTRATE (PIN 16) TO GROUND
13
15
10
11
= 1N4148
2k
750Ω
0.1µF
510Ω
12
14
Q4
5V
Q3
2
36Ω
470Ω
0
+
+
0
10
20
30
40
50
2k
0.1µF
10µF
100µF
OVERDRIVE (mV)
+
TRIGGER
OUT
0.1µF
LT1394
1394 TA02
470Ω
–
INPUT
1394 F18
1