LT1719
4.5ns Single/Dual Supply
3V/5V Comparator with
Rail-to-Rail Output
FEATURES
s
s
s
s
DESCRIPTIO
s
s
s
UltraFast: 4.5ns at 20mV Overdrive
7ns at 5mV Overdrive
Low Power: 4.2mA at 3V
SOT-23 Package
Separate Input and Output Power Supplies
(SO-8 Only)
Output Optimized for 3V and 5V Supplies
TTL/CMOS Compatible Rail-to-Rail Output
Low Power Shutdown Mode: 0.1µA
APPLICATIO S
s
s
s
s
s
s
s
High Speed Differential Line Receiver
Crystal Oscillator Circuits
Level Translators
Threshold Detectors/Discriminators
Zero-Crossing Detectors
High Speed Sampling Circuits
Delay Lines
The LT
®
1719 is an UltraFast
TM
comparator optimized for low
voltage operation. The input voltage range extends from
100mV below V
EE
to 1.2V below V
CC
. Internal hysteresis
makes the LT1719 easy to use even with slow moving input
signals. The rail-to-rail outputs directly interface to TTL and
CMOS. Alternatively the symmetric output drive can be
harnessed for analog applications or for easy translation to
other single supply logic levels. A shutdown control allows
for reduced power consumption and extended battery life in
portable applications.
The LT1719 is available in the SO-8 and 6-lead SOT-23
package. The SO-8 package has separate supplies which
allow flexible operation, accomodating separate analog input
ranges and output logic levels.
For a dual/quad comparator with similar performance, see
the LT1720/LT1721.
, LTC and LT are registered trademarks of Linear Technology Corporation.
UltraFast is a trademark of Linear Technology Corporation.
TYPICAL APPLICATION
2.7V to 6V Crystal Oscillator with TTL/CMOS Output
2.7V TO 6V
2k
220Ω
1MHz TO 10MHz
CRYSTAL (AT-CUT)
8
7
6
GROUND
CASE
OUTPUT
RISING EDGE
(t
PDLH
)
25°C
V
STEP
= 100mV
V
+
= 5V
C
LOAD
= 10pF
Propagation Delay vs Overdrive
DELAY (ns)
620Ω
5
4
3
2
FALLING EDGE
(t
PDHL
)
+
–
C1
LT1719
2k
1719 TA01
1
0
0
10
20
30
OVERDRIVE (mV)
40
50
1719 TA02
0.1µF
1.8k
U
U
U
1
LT1719
ABSOLUTE
MAXIMUM
RATINGS
(Note 1)
PACKAGE/ORDER INFORMATION
TOP VIEW
V
CC
1
+IN 2
–IN 3
V
EE
4
+
–
Supply Voltage
+ V
S
to GND (LT1719S8) ...................................... 7V
V
CC
to V
EE
(LT1719S8) ....................................... 12V
+ V
S
to V
EE
(LT1719S8) ...................................... 12V
V
EE
to GND (LT1719S8) ...................... – 12V to 0.3V
V
+
to V
–
(LT1719S6) ............................................. 7V
Input Current (+ IN, – IN or SHDN).....................
±10mA
Output Current (Continuous) ............................
±20mA
Operating Temperature Range
C Grade .................................................. 0°C to 70°C
I Grade .............................................. – 40°C to 85°C
Junction Temperature .......................................... 150°C
Storage Temperature Range ................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
ORDER PART
NUMBER
8
7
6
5
+ V
S
OUT
SHDN
GND
LT1719CS8
LT1719IS8
S8 PART MARKING
1719
1719I
ORDER PART
NUMBER
S8 PACKAGE
8-LEAD PLASTIC SO
T
JMAX
= 150°C,
θ
JA
= 110°C/ W
TOP VIEW
–IN 1
V 2
+IN 3
–
6 SHDN
5 OUT
4 V
+
LT1719CS6
LT1719IS6
S6 PART MARKING
LTHW
LTJF
S6 PACKAGE
6-LEAD PLASTIC SOT-23
T
JMAX
= 150°C,
θ
JA
= 230°C/ W
Consult factory for parts specified with wider operating temperature ranges.
The
q
denotes specifications that apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C. V
CM
= 1V, V
SHDN
= 0.5V, V
OVERDRIVE
= 20mV, C
OUT
= 10pF and for the LT1719S8
V
CC
= +V
S
= 5V and V
EE
= –5V, for the LT1719S6 V
+
= 5V, V
–
= 0V, unless otherwise specified.
SYMBOL
V
CC
– V
EE
+ V
S
V
+
– V
–
V
CMR
V
TRIP+
V
TRIP–
V
OS
V
HYST
∆V
OS
/∆T
I
B
I
OS
CMRR
PSRR
A
V
V
OH
PARAMETER
Input Supply Voltage
Output Supply Voltage
Supply Voltage
Input Voltage Range
Input Trip Points
Input Offset Voltage
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
(Note 4)
(Note 5)
(Note 6)
(Note 7)
(Note 8)
I
SOURCE
= 4mA, V
IN
= V
TRIP+
+ 10mV
(LT1719S8)
(LT1719S6)
q
+ V
S
– 0.4
q
V
+
– 0.4
ELECTRICAL CHARACTERISTICS
CONDITIONS
(LT1719S8 only)
(LT1719S8 only)
(LT1719CS6 only)
(Note 2)
(Note 3)
(Note 3)
q
q
q
q
q
q
q
q
MIN
2.7
2.7
2.7
V
EE
– 0.1
V
–
– 0.1
– 1.5
– 5.5
TYP
MAX
10.5
6
6
V
CC
– 1.2
V
+
– 1.2
5.5
1.5
UNITS
V
V
V
V
V
mV
mV
mV
mV
mV
µV/°C
µA
µA
dB
dB
dB
dB
V
V
(LT1719S8)
(LT1719S6)
0.4
q
q
q
q
2.5
3.5
7
0
0.6
(Note 3)
2.0
–6
55
55
65
65
3.5
10
–2.5
0.2
70
65
80
80
(LT1719S8)
(LT1719S6)
(LT1719S8)
(LT1719S6)
q
q
∞
2
U
W
U
U
W W
W
LT1719
The
q
denotes specifications that apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C. V
CM
= 1V, V
SHDN
= 0.5V, V
OVERDRIVE
= 20mV, C
OUT
= 10pF and for the LT1719S8
V
CC
= +V
S
= 5V and V
EE
= –5V, for the LT1719S6 V
+
= 5V, V
–
= 0V, unless otherwise specified.
SYMBOL PARAMETER
V
OL
t
PD20
Output Low Voltage
Propagation Delay
CONDITIONS
I
SINK
= 10mA, V
IN
= V
TRIP–
– 10mV
V
OVERDRIVE
= 20mV (Note 9)
V
OVERDRIVE
= 20mV, V
EE
= – 5V
t
PD5
t
SKEW
t
r
t
f
t
JITTER
f
MAX
t
OFF
t
ON
I
CC
I
EE
I
S
I
+
I
SHDN5
I
SHDN3
I
CCS
I
SS
I
EES
I
+S
I
CCSO
I
SSO
I
EEO
I
+O
Propagation Delay
Propagation Delay Skew
Output Rise Time
Output Fall Time
Output Timing Jitter
Maximum Toggle Frequency
Turn-Off Delay
Wake-Up Delay
Positive Input Stage Supply Current
q
ELECTRICAL CHARACTERISTICS
MIN
V
EE
= 0V(LT1719S8)
V
–
= 0V(LT1719S6)
q
(LT1719S8 only)
TYP
4.5
4.2
7
0.5
2.5
2.2
MAX
0.4
6.5
8.0
10
13
1.5
UNITS
V
ns
ns
ns
ns
ns
ns
ns
ns
ps
RMS
ps
RMS
MHz
MHz
ns
ns
V
OVERDRIVE
= 5mV (Notes 9, 10) V
EE
= 0V(LT1719S8)
V
–
= 0V(LT1719S6)
q
(Note 11)
10% to 90%
90% to 10%
V
IN
= 1.2V
P-P
(6dBm), Z
IN
= 50Ω
f = 20MHz
V
OVERDRIVE
= 50mV, +V
S
or V
+
= 3V
V
OVERDRIVE
= 50mV, +V
S
or V
+
= 5V
Time to Z
OUT
≥10kΩ
Time to V
OH
or V
OL
, I
LOAD
= 1mA
+ V
S
= V
CC
= 5V, V
EE
= – 5V
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
t
PD+
t
PD–
15
11
70
62.5
75
350
1.0
0.9
– 4.8
– 3.8
– 2.6
– 2.2
4.2
3.3
4.6
4.2
–300
–200
–110
–80
0.2
7
– 0.2
7
0.1
0.1
0.1
0.2
8
6
9
7
–30
–20
30
50
80
20
20
40
2.2
1.8
mA
mA
mA
mA
mA
mA
mA
mA
µA
µA
µA
µA
µA
µA
µA
µA
µA
µA
(LT1719S8 0nly) + V
S
= V
CC
= 3V, V
EE
= 0V
Negative Input Stage Supply Current + V
S
= V
CC
= 5V, V
EE
= – 5V
(LT1719S8 0nly) + V
S
= V
CC
= 3V, V
EE
= 0V
Positive Output Stage Supply Current + V
S
= V
CC
= 5V, V
EE
= – 5V
(LT1719S8 0nly) V
S
= V
CC
= 3V, V
EE
= 0V
Supply Current
Shutdown Pin Current
Shutdown Pin Current
(LT1719S6) V
+
= 5V
V
+
= 3V
+V
S
or V
+
= 5V
+V
S
or V
+
= 3V
Disabled Supply Currents (LT1719S8) + V
S
= 6V, V
CC
= 5V, V
EE
= – 5V
(LT1719S8) V
SHDN
= +V
S
– 0.5V
(LT1719S8)
(LT1719S6) V
+
= 6V, V
SHDN
= +V
S
– 0.5V
(LT1719S8) + V
S
= 6V, V
CC
= 5V, V
EE
= – 5V
(LT1719S8) Shutdown Pin Open
(LT1719S8)
(LT1719S6) V
+
= 6V, Shutdown Pin Open
– 30
– 20
Note 1:
Absolute Maximum Ratings are those values beyond which the
life of a device may be impaired.
Note 2:
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 3:
The LT1719 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 4:
The LT1719S8 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 5:
The LT1719S6 common mode rejection ratio is measured
with V
+
= 5V and is defined as the change in offset voltage measured
from V
CM
= –0.1V to V
CM
= 3.8V, divided by 3.9V.
Note 6:
The LT1719S8 power supply rejection ratio is measured with
V
CM
= 1V and is defined as the worst of: the change in offset voltage
from V
EE
= – 5.5V to V
EE
= 0V divided by 5.5V, or 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.
Note 7:
The 1719S6 power supply rejection ratio is measured with
V
CM
= 1V and is defined as the change in offset voltage measured from
V
+
= 2.7V to V
+
= 6V, divided by 3.3V.
3
LT1719
ELECTRICAL CHARACTERISTICS
Note 8:
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 10mV of overdrive.
Note 9:
Propagation delay measurements made with 100mV steps.
Overdrive is measured relative to V
TRIP
±
.
Note 10:
t
PD
cannot be measured in automatic handling equipment
with low values of overdrive. The LT1719 is 100% tested with a
100mV step and 20mV overdrive. Correlation tests have shown that
t
PD
limits can be guaranteed with this test, if additional DC tests are
performed to guarantee that all internal bias conditions are correct.
Note 11:
Propagation Delay Skew is defined as:
t
SKEW
= |t
PDLH
– t
PDHL
|
TYPICAL PERFORMANCE CHARACTERISTICS
Input Offset and Trip Voltages
vs Supply Voltage
3
V
OS
AND TRIP POINT VOLTAGE (mV)
COMMON MODE INPUT VOLTAGE (V)
V
OS
AND TRIP POINT VOLTAGE (mV)
V
TRIP
2
1
V
OS
0
–1
–2
25°C
V
CM
= 1V
V
EE
OR V
–
= GND
+
V
TRIP–
–3
2.5
5.5
6.0
5.0
3.0
3.5 4.0 4.5
SUPPLY VOLTAGE, V
CC
= + V
S
OR V
+
(V)
1719 G01
Input Current
vs Differential Input Voltage
2
25°C
1
SUPPLY CURRENT (mA)
6
4
2
0
–2
–4
I
EE
(LT1719S8)
0
25
50
75
100
125
I
CC
(LT1719S8)
+I
S
(LT1719S8)
SUPPLY CURRENTS (mA)
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
4
U W
1719 G04
Input Offset and Trip Voltages
vs Temperature
3
2
1
V
OS
0
–1
–2
V
TRIP+
4.2
4.0
3.8
0
– 0.2
– 5.0
– 5.2
Input Common Mode Limits
vs Temperature
+V
S
= V
CC
OR V
+
= 5V
V
–
= GND (LT1719S6)
V
TRIP–
+V
S
= V
CC
or V
+
= 5V
V
CM
= 1V
V
EE
OR V
–
= GND
V
EE
= –5V (LT1719S8)
50
25
75
0
TEMPERATURE (°C)
100
125
–3
– 60 – 40 – 20 0 20 40 60 80 100 120 140
TEMPERATURE (°C)
1719 G02
– 5.4
– 50 – 25
1719 G03
Quiescent Supply Current
vs Temperature
10
V
CC
= +V
S
OR V
+
= 5V
8 V
EE
= GND
6
Quiescent Supply Current
vs Supply Voltage
5
4
3
2
1
0
–1
–2
–3
0
I
EE
(LT1719S8)
1
3
4
5
6
2
SUPPLY VOLTAGE, V
CC
= +V
S
OR V
+
(V)
7
I
CC
(LT1719S8)
I
S
(LT1719S8)
T
A
= 25°C
V
EE
= GND
I
+
(LT1719S6)
I
+
(LT1719S6)
–6
–50 –25
TEMPERATURE (°C)
1339 G05
1719 G06
LT1719
TYPICAL PERFORMANCE CHARACTERISTICS
Propagation Delay
vs Load Capacitance
9
8
PROPAGATION DELAY (ns)
8.0
PROPAGATION DELAY (ns)
7
6
5
4
3
2
1
0
0
7.0
6.5
6.0
5.5
5.0
4.5
4.0
– 50 – 25
0
PROPAGATION DELAY (ns)
25°C
V
STEP
= 100mV
OVERDRIVE = 20mV
+V
S
= V
CC
OR V
+
= 5V
V
EE
OR V
–
= 0V
RISING EDGE
(t
PDLH
)
FALLING EDGE
(t
PDHL
)
40
30
OUTPUT LOAD CAPACITANCE (pF)
10
20
Output Low Voltage
vs Load Current
0.5
OUTPUT VOLTAGE RELATIVE TO +V
S
(V)
+V
S
OR V
+
= 5V
V
IN
= – 10mV
125°C
125°C
V
CC
= 2.7V
25°C
– 55°C
OUTPUT VOLTAGE (V)
0.4
+V
S
SUPPLY CURRENT (mA)
0.3
0.2
0.1
0
4
12
16
8
OUTPUT SINK CURRENT (mA)
Shutdown Currents
vs Shutdown Voltage
4
I
S
SUPPLY
CURRENTS (mA)
SUPPLY I
+
CURRENT (mA)
3
LT1719S8
2
1
I
CC
0
– 50
T
A
= 25°C
V
EE
= GND
+V
S
= V
CC
= 5V
SHDN PIN
CURRENT (µA)
SHDN PIN
CURRENT (µA)
–100
V
S
– 4
U W
Propagation Delay
vs Temperature
7.5
t
PDLH
V
CM
= 1V
V
STEP
= 100mV
C
LOAD
= 10pF
V
EE
OR V
–
= GND
+V
S
= V
CC
= V
+
3V
5V
OVERDRIVE = 5mV
OVERDRIVE = 20mV
3V
5V
Propagation Delay
vs Supply Voltage
5.5
25°C
V
STEP
= 100mV
OVERDRIVE = 20mV
C
LOAD
= 10pF
V
EE
/V
–
= GND
5.0
t
TPLH
t
TPHL
4.5
t
TPLH
4.0
t
TPHL
V
EE
= –5V
(V
CC
, +V
S
= 5.5V
MAX
)
(LT1719S8 ONLY)
3.5
2.5
5.5 6.0
5.0
3.0
3.5 4.0 4.5
SUPPLY VOLTAGE, +V
S
= V
CC
OR V
+
(V)
1719 G09
50
1719 G07
75
50
25
TEMPERATURE (°C)
100
125
1719
G08
Output High Voltage
vs Load Current
0.0
125°C
+V
S
OR V
+
= 5V
V
IN
= 10mV
9
8
7
Supply Current vs Frequency
25°C
+ V
S
= 5V
– 0.2
– 55°C
– 0.4
25°C
C
LOAD
= 20pF
6
5
4
NO LOAD
3
2
C
LOAD
= 10pF
– 0.6
– 0.8
25°C
V
CC
= 2.7V
–1.0
0
4
12
16
8
OUTPUT SOURCE CURRENT (mA)
20
1719 G11
20
1719 G10
0
10
20
FREQUENCY (MHz)
30
40
1719 G12
Shutdown Currents
vs Shutdown Voltage
5
4
LT1719S6
3
2
1
0
– 50
T
A
= 25°C
V
+
= 5V
V
+
– 3
V
+
– 2
V
+
– 1
SHDN PIN VOLTAGE (V)
V
+
1719 G13b
V
S
– 3
V
S
– 2
V
S
– 1
SHDN PIN VOLTAGE (V)
V
S
1719 G13a
–100
V
+
– 4
5
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