FEATURES
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LT1715
4ns, 150MHz
Dual Comparator with
Independent Input/Output Supplies
DESCRIPTION
The LT
®
1715 is an UltraFast™ dual comparator optimized for
low voltage operation. Separate supplies allow independent
analog input ranges and output logic levels with no loss of
performance. The input voltage range extends from 100mV
below V
EE
to 1.2V below V
CC
. Internal hysteresis makes the
LT1715 easy to use even with slow moving input signals.
The rail-to-rail outputs directly interface toTTL and CMOS.
The symmetric output drive results in similar rise and fall
times that can be harnessed for analog applications or for
easy translation to other single supply logic levels.
The LT1715 is available in the 10-pin MSOP package. The
pinout of the LT1715 minimizes parasitic effects by placing
the most sensitive inputs away from the outputs, shielded
by the power rails.
For a dual/quad single supply comparator with simi-
lar propagation delay, see the LT1720/LT1721. For a
single comparator with similar propagation delay, see
the LT1719.
L,
LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
UltraFast is a trademark of Linear Technology Corporation.
UltraFast: 4ns at 20mV Overdriven
150MHz Toggle Frequency
Separate Input and Output Power Supplies
Low Power: 4.6mA per Comparator at 3V
Pinout Optimized for High Speed Use
Output Optimized for 3V and 5V Supplies
TTL/CMOS Compatible Rail-to-Rail Output
Input Voltage Range Extends 100mV
Below Negative Rail
Internal Hysteresis with Specified Limits
Specified for –40°C to 125°C Temperature Range
Available in the 10-pin MSOP Package
APPLICATIONS
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High Speed Differential Line Receivers
Level Translators
Window Comparators
Crystal Oscillator Circuits
Threshold Detectors/Discriminators
High Speed Sampling Circuits
Delay Lines
TYPICAL APPLICATION
100MHz Dual Differential Line Receiver
5V
3V
Line Receiver Response to 100MHz Clock,
50MHz Data Both with 25mV
P-P
Inputs
3V
CLOCK OUT
+
IN A
OUT A
1V/DIV
–
0V
3V
+
IN B
OUT B
DATA OUT
0V
5ns/DIV
1715 TA02
1V/DIV
–
–5V
1715 TA01
FET PROBES
1715fa
1
LT1715
ABSOLUTE MAXIMUM RATINGS
(Note 1)
PIN CONFIGURATION
TOP VIEW
+IN A
–IN A
–IN B
+IN B
V
EE
1
2
3
4
5
A
B
10
9
8
7
6
V
CC
+V
S
OUT A
OUT B
GND
Supply Voltage
+V
S
to GND .............................................................7V
V
CC
to V
EE
..........................................................13.2V
+V
S
to V
EE
..........................................................13.2V
V
EE
to GND ......................................... –13.2V to 0.3V
Input Current (+IN, –IN) .......................................±10mA
Output Current (Continuous) ...............................±20mA
Operating Temperature Range (Note 2)
LT1715C............................................... –40°C to 85°C
LT1715I ................................................ –40°C to 85°C
LT1715H ............................................ –40°C to 125°C
Specified Temperature Range (Note 3)
LT1715C................................................... 0°C to 70°C
LT1715I ................................................ –40°C to 85°C
LT1715H ............................................ –40°C to 125°C
Junction Temperature ........................................... 150°C
Storage Temperature Range................... –65°C to 150°C
Lead Temperature (Soldering, 10 sec) .................. 300°C
MS PACKAGE
10-LEAD PLASTIC MSOP
T
JMAX
= 150°C,
θ
JA
= 120°C/W (NOTE 4)
ORDER INFORMATION
LEAD FREE FINISH
LT1715CMS#PBF
LT1715IMS#PBF
LT1715HMS#PBF
TAPE AND REEL
LT1715CMS#TRPBF
LT1715IMS#TRPBF
LT1715HMS#TRPBF
PART MARKING
LTVQ
LTVV
LTVV
PACKAGE DESCRIPTION
10-Lead Plastic MSOP
10-Lead Plastic MSOP
10-Lead Plastic MSOP
SPECIFIED TEMPERATURE RANGE
0°C to 70°C
–40°C to 85°C
–40°C to 125°C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/
The
l
denotes the specifications which apply over the full operating
,
temperature range, otherwise specifications are at T
A
= 25°C. V
CC
= 5V, V
EE
= –5V, +V
S
= 5V, V
CM
= 1V, C
OUT
= 10pF V
OVERDRIVE
= 20mV,
unless otherwise specified.
SYMBOL
V
CC
– V
EE
+V
S
V
CMR
V
TRIP+
V
TRIP–
PARAMETER
Input Supply Voltage
Output Supply Voltage
Input Voltage Range
Input Trip Points
Input Trip Points
(Note 5)
(Note 6)
(Note 6)
LT1715C, LT1715I
LT1715H
LT1715C, LT1715I
LT1715H
CONDITIONS
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ELECTRICAL CHARACTERISTICS
MIN
2.7
2.7
V
EE
– 0.1
–1.5
–1.8
–5.5
–6
TYP
MAX
12
6
V
CC
– 1.2
5.5
6
1.5
1.8
UNITS
V
V
V
mV
mV
mV
mV
1715fa
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LT1715
ELECTRICAL CHARACTERISTICS
SYMBOL
V
OS
PARAMETER
Input Offset Voltage
The
l
denotes the specifications which apply over the full operating
,
temperature range, otherwise specifications are at T
A
= 25°C. V
CC
= 5V, V
EE
= –5V, +V
S
= 5V, V
CM
= 1V, C
OUT
= 10pF V
OVERDRIVE
= 20mV,
unless otherwise specified.
CONDITIONS
(Note 6)
LT1715C, LT1715I
LT1715H
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MIN
TYP
0.4
MAX
2.5
3.5
4
6
7
0
0
0.6
1
UNITS
mV
mV
mV
mV
mV
μV/°C
μA
μA
μA
μA
dB
dB
dB
V
V
HYST
V
OS
/ΔT
I
B
I
OS
CMRR
PSRR
A
V
V
OH
V
OL
f
MAX
t
PD20
Input Hysteresis Voltage
Input Offset Voltage Drift
Input Bias Current
Input Offset Current
Common Mode Rejection Ratio
Power Supply Rejection Ratio
Voltage Gain
Output High Voltage
Output Low Voltage
Maximum Toggle Frequency
Propagation Delay
(Note 6)
LT1715C, LT1715I
LT1715H
LT1715C, LT1715I
LT1715H
LT1715C, LT1715I
LT1715H
2
2
–6
–7
3.5
10
–2.5
0.2
(Note 7)
(Note 8)
(Note 9)
LT1715C, LT1715I
LT1715H
60
55
65
+V
S
– 0.4
70
80
∞
0.4
150
I
SOURCE
= 4mA, V
IN
= V
TRIP+
+ 20mV
I
SINK
= 10mA, V
IN
= V
TRIP–
– 20mV
(Note 10)
V
OVERDRIVE
= 20mV (Note 11),
V
CC
= 5V, V
EE
= –5V
LT1715C, LT1715I
LT1715H
V
OVERDRIVE
= 20mV, V
CC
= 5V, V
EE
= 0V
V
OVERDRIVE
= 20mV, V
CC
= 3V, V
EE
= 0V
LT1715C, LT1715I
LT1715H
V
MHz
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ps
RMS
ps
RMS
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2.8
2.8
2.8
3
3
3
4
6
7
8
6.5
7.5
8
9
12
1.5
1
4.4
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4.8
t
PD5
t
SKEW
Δt
PD
t
r
t
f
t
JITTER
I
CC
Propagation Delay
Propagation Delay Skew
Differential Propagation Delay
Output Rise Time
Output Fall Time
Output Timing Jitter
Positive Input Stage Supply Current
(per Comparator)
V
OVERDRIVE
= 5mV, V
EE
= 0V (Notes 11, 12)
(Note 13) Between t
PD+
/t
PD–
, V
EE
= 0V
(Note 14) Between Channels
10% to 90%
90% to 10%
V
IN
= 1.2V
P-P
(6dBm), Z
IN
= 50
f = 20MHz (Note 15)
t
PD+
t
PD–
6
0.5
0.3
2
2
15
11
+V
S
= V
CC
= 5V, V
EE
= –5V LT1715C, LT1715I
LT1715H
+V
S
= V
CC
= 3V, V
EE
= 0V
LT1715C, LT1715I
LT1715H
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1
0.9
–4.8
–5.3
–3.8
–4.3
–2.9
–2.4
4.6
3.7
2
2.2
1.6
1.8
mA
mA
mA
mA
mA
mA
mA
mA
I
EE
Negative Input Stage Supply Current
(per Comparator)
+V
S
= V
CC
= 5V, V
EE
= –5V LT1715C, LT1715I
LT1715H
+V
S
= V
CC
= 3V, V
EE
= 0V
LT1715C, LT1715I
LT1715H
I
S
Positive Output Stage Supply Current
(per Comparator)
+V
S
= V
CC
= 5V, V
EE
= –5V LT1715C, LT1715I
LT1715H
V
S
= V
CC
= 3V, V
EE
= 0V
LT1715C, LT1715I
LT1715H
7.5
8
6
6.5
mA
mA
mA
mA
1715fa
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LT1715
ELECTRICAL CHARACTERISTICS
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2:
The LT1715C is guaranteed functional over the operating range of
–40°C to 85°C.
Note 3:
The LT1715C is guaranteed to meet specified performance from
0°C to 70°C. The LT1715°C is designed, characterized and expected to
meet specified performance from –40°C to 85°C but is not tested or
QA sampled at these temperatures. The LT1715I is guaranteed to meet
specified performance from –40°C to 85°C. The LT1715H is guaranteed to
meet specified performance from –40°C to 125°C.
Note 4:
Thermal resistances vary depending upon the amount of PC board
metal attached to Pin 5 of the device.
θ
JA
is specified for a 2500mm
2
3/32"
FR-4 board covered with 2oz copper on both sides and with 100mm
2
of
copper attached to Pin 5. Thermal performance can be improved beyond
the given specification by using a 4-layer board or by attaching more metal
area to Pin 5.
Note 5:
If one input is within these common mode limits, the other input
can go outside the common mode limits and the output will be valid.
Note 6:
The LT1715 comparator includes internal hysteresis. The trip
points are the input voltage needed to change the output state in each
direction. The offset voltage is defined as the average of V
TRIP+
and V
TRIP–
,
while the hysteresis voltage is the difference of these two.
Note 7:
The common mode rejection ratio is measured with V
CC
= 5V,
V
EE
= –5V and is defined as the change in offset voltage measured from
V
CM
= –5.1V to V
CM
= 3.8V, divided by 8.9V.
Note 8:
The power supply rejection ratio is measured with V
CM
= 1V and is
defined as the worst of: the change in offset voltage from V
CC
= +V
S
= 2.7V
to V
CC
= +V
S
= 6V (with V
EE
= 0V) divided by 3.3V or the change in offset
voltage from V
EE
= 0V to V
EE
= –6V (with V
CC
= +V
S
= 6V) divided by 6V.
Note 9:
Because of internal hysteresis, there is no small-signal region in
which to measure gain. Proper operation of internal circuity is ensured by
measuring V
OH
and V
OL
with only 20mV of overdrive.
Note 10:
Maximum toggle rate is defined as the highest frequency at
which a 100mV sinusoidal input results in an error free output toggling to
greater than 4V when high and to less than 1V when low on a 5V output
supply.
Note 11:
Propagation delay measurements made with 100mV steps.
Overdrive is measured relative to V
TRIP±
.
Note 12:
t
PD
cannot be measured in automatic handling equipment with
low values of overdrive. The LT1715 is 100% tested with a 100mV step
and 20mV overdrive. Correlation tests have shown that t
PD
limits can be
guaranteed with this test.
Note 13:
Propagation Delay Skew is defined as:
t
SKEW
= |t
PDLH
– t
PDHL
|
Note 14:
Differential propagation delay is defined as the larger of the two:
Δt
PDLH
= |t
PDLHA
– t
PDLHB
|
Δt
PDHL
= |t
PDHLA
– t
PDHLB
|
Note 15:
Package inductances combined with asynchronous activity on
the other channel can increase the output jitter. See Channel Interactions
in Applications Information. Specification above is with one channel active
only.
TYPICAL PERFORMANCE CHARACTERISTICS
Input Offset and Trip Voltages
vs Supply Voltage
3
V
OS
AND TRIP POINT VOLTAGE (mV)
V
OS
AND TRIP POINT VOLTAGE (mV)
V
TRIP+
2
1
V
OS
0
–1
–2
T
A
= 25°C
V
CM
= 1V
V
EE
= GND
5.5
5.0
3.0
3.5 4.0 4.5
SUPPLY VOLTAGE, V
CC
= +V
S
(V)
6.0
3
2
1
0
–1
V
TRIP–
–2
–3
–60 –40 –20 0 20 40 60 80 100 120 140
TEMPERATURE (°C)
1715 G02
Input Offset and Trip Voltages
vs Temperature
COMMON MODE INPUT VOLTAGE (V)
+V
S
= V
CC
= 5V
V
CM
= 1V
V
EE
= –5V
V
TRIP+
V
OS
4.2
4.0
3.8
3.6
–4.8
–5.0
–5.2
Input Common Mode Limits
vs Temperature
+V
S
= V
CC
= 5V
V
EE
= –5V
V
TRIP–
–3
2.5
–5.4
–50 –25
50
25
75
0
TEMPERATURE (°C)
100
125
1715 G01
1715 G03
1715fa
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LT1715
TYPICAL PERFORMANCE CHARACTERISTICS
Input Current
vs Differential Input Voltage
SUPPLY CURRENT PER COMPARATOR (mA)
2
1
0
INPUT BIAS (μA)
–1
–2
–3
–4
–5
–6
–7
–5 –4 –3 –2 –1 0 1 2 3 4
DIFFERENTIAL INPUT VOLTAGE (V)
5
T
A
= 25°C
V
CC
= +V
S
= 5V
V
EE
= –5V
8
6
4
2
0
–2
I
EE
–4
–6
–50 –25
I
CC
Quiescent Supply Current
vs Temperature
SUPPLY CURRENT PER COMPARATOR (mA)
V
CC
= +V
S
= 5V
V
EE
= –5V
I
S
6
5
4
3
2
1
0
–1
–2
–3
–4
Quiescent Supply Current
vs Supply Voltage
T
A
= 25°C
V
EE
= GND
I
S
, OUTPUT HIGH
I
S
, OUTPUT LOW
I
CC
I
EE
, OUTPUT LOW
I
EE
, OUTPUT HIGH
0
4
3
2
5
6
1
SUPPLY VOLTAGE, V
CC
= +V
S
(V)
7
1715 G06
0
75
50
25
TEMPERATURE (°C)
100
125
1715 G04
1715 G05
0.5
TOTAL SUPPLY CURRENT PER COMPARATOR (mA)
Output Low Voltage
vs Load Current
OUTPUT VOLTAGE RELATIVE TO +V
S
(V)
V
CC
= +V
S
= 5V, UNLESS
125°C
OTHERWISE NOTED
+V
S
= 2.7V
V
IN
= –10mV
125°C
0.3
–55°C
0.2
25°C
–0.1
Output High Voltage
vs Load Current
V
CC
= +V
S
= 5V, UNLESS
OTHERWISE NOTED
V
IN
= 10mV
–55°C
–0.3
25°C
–0.4
125°C
–0.5
125°C
+V
S
= 2.7V
–0.6
0
4
12
16
8
OUTPUT SOURCE CURRENT (mA)
20
1715 G08
Supply Current
vs Toggle Frequency
30
25
C
LOAD
= 20pF
20
15
C
LOAD
= 0pF
10
5
0
0
25
T
A
= 25°C
V
IN
= ±50mV SINUSOID
+V
S
= V
CC
= 5V
V
EE
= GND
50 75 100 125 150 175 200 225
TOGGLE FREQUENCY (MHz)
1715 G09
VALID
TOGGLING
INCOMPLETE
OUTPUT TOGGLING
0.4
OUTPUT VOLTAGE (V)
–0.2
C
LOAD
= 10pF
0.1
0
0
4
12
16
8
OUTPUT SINK CURRENT (mA)
20
1715 G07
Propagation Delay
vs Overdrive
8
T
A
= 25°C
V
STEP
= 100mV
C
LOAD
= 10pF
V
CC
= +V
S
= 3V
V
EE
= 0V
8.0
7.5
PROPAGATION DELAY (ns)
7.0
6.5
6.0
5.5
5.0
4.5
4.0
Propagation Delay
vs Temperature
t
PDLH
C
LOAD
= 10pF
V
STEP
= 100mV
PROPAGATION DELAY (ns)
5.5
Propagation Delay
vs Supply Voltage
T
A
= 25°C
V
STEP
= 100mV
OVERDRIVE = 20mV
C
LOAD
= 10pF
t
PDLH
4.5
t
PDHL
t
PDLH
4.0
t
PDHL
3.5
2.5
V
EE
= –5V
V
EE
= GND
PROPAGATION DELAY (ns)
7
5.0
OVERDRIVE = 5mV
6
V
CC
= +V
S
= 3V
V
EE
= 0V
5
t
PDLH
t
PDHL
t
PDLH
V
CC
= +V
S
= 5V
V
EE
= –5V
0
10
30
OVERDRIVE (mV)
20
40
t
PDHL
50
1715 G10
4
3.5 OVERDRIVE = 20mV
3.0
–50 –25
0
V
CC
= +V
S
= 5V
V
EE
= –5V
100
125
3
50
75
25
TEMPERATURE (°C)
5.5
6.0
5.0
3.0
3.5 4.0 4.5
+
(V)
SUPPLY VOLTAGE, +V
S
= V
CC
OR V
1715 G12
1715 G11
1715fa
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