LINEAR TECHNOLOGY LT1719 Technical data

FEATURES

■

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

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APPLICATIO S

■

High Speed Differential Line Receiver

■

Crystal Oscillator Circuits

■

Level Translators

■

Threshold Detectors/Discriminators

■

Zero-Crossing Detectors

■

High Speed Sampling Circuits

■

Delay Lines

LT1719

4.5ns Single/Dual Supply
3V/5V Comparator with

Rail-to-Rail Output

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DESCRIPTIO

The LT®1719 is an UltraFastTM comparator optimized for low
voltage operation. The input voltage range extends from
100mV below VEE to 1.2V below VCC. 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.

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TYPICAL APPLICATION

2.7V to 6V Crystal Oscillator with TTL/CMOS Output

2.7V TO 6V

2k

620Ω

1MHz TO 10MHz

CRYSTAL (AT-CUT)

220Ω

+

C1

LT1719

–

0.1µF 1.8k

GROUND

CASE

2k

1719 TA01

OUTPUT

Propagation Delay vs Overdrive

8

7

RISING EDGE

6

5

4

DELAY (ns)

3

2

1

0

0

)

(t

PDLH

FALLING EDGE

10 20 40

OVERDRIVE (mV)

25°C

= 100mV

V

STEP
+

= 5V

V

= 10pF

C

LOAD

(t

)

PDHL

30

50

1719 TA02

1

LT1719

TOP VIEW

+V

S

OUT
SHDN
GND

V

CC

+IN
–IN

V

EE

S8 PACKAGE

8-LEAD PLASTIC SO

1

2

3

4

8

7

6

5

+

–

–IN 1
V

–

2

+IN 3

6 SHDN
5 OUT
4 V

+

TOP VIEW

S6 PACKAGE

6-LEAD PLASTIC SOT-23

WW

W

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ABSOLUTE MAXIMUM RATINGS

(Note 1)

Supply Voltage

+VS to GND (LT1719S8) ...................................... 7V

VCC to VEE (LT1719S8)....................................... 12V

+VS to VEE (LT1719S8) ...................................... 12V

VEE 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

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W

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PACKAGE/ORDER INFORMATION

ORDER PART

NUMBER

LT1719CS8
LT1719IS8

S8 PART MARKING

T

= 150°C, θJA = 110°C/W

JMAX

S6 PART MARKING

T

= 150°C, θJA = 230°C/W

JMAX

Consult factory for parts specified with wider operating temperature ranges.

1719
1719I

ORDER PART

NUMBER

LT1719CS6
LT1719IS6

LTHW
LTJF

ELECTRICAL CHARACTERISTICS

range, otherwise specifications are at T
VCC = +VS = 5V and VEE = –5V, for the LT1719S6 V+ = 5V, V– = 0V, unless otherwise specified.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

V

CC

+V
V+ – V
V

CMR

V

TRIP

V

TRIP

V

OS

V

HYST

∆VOS/∆T Input Offset Voltage Drift ● 10 µV/°C
I

B

I

OS

CMRR Common Mode Rejection Ratio (Note 4) (LT1719S8) ● 55 70 dB

PSRR Power Supply Rejection Ratio (Note 6) (LT1719S8) 65 80 dB

A

V

V

OH

2

The ● denotes specifications that apply over the full operating temperature

= 25°C. V

A

– V

S

–

+
–

Input Supply Voltage (LT1719S8 only) ● 2.7 10.5 V

EE

Output Supply Voltage (LT1719S8 only) ● 2.7 6 V
Supply Voltage (LT1719CS6 only) ● 2.7 6 V
Input Voltage Range (Note 2) (LT1719S8) ● VEE – 0.1 VCC – 1.2 V

Input Trip Points (Note 3) ● –1.5 5.5 mV

Input Offset Voltage (Note 3) 0.4 2.5 mV

Input Hysteresis Voltage (Note 3) ● 2.0 3.5 7 mV

Input Bias Current ● –6 –2.5 0 µA
Input Offset Current ● 0.2 0.6 µA

Voltage Gain (Note 8) ∞
Output High Voltage I

= 1V, V

CM

(Note 5) (LT1719S6)

(Note 7) (LT1719S6) 65 80 dB

= 4mA, VIN = V

SOURCE

SHDN

= 0.5V, V

TRIP

OVERDRIVE

+

+ 10mV (LT1719S8) ● +VS – 0.4 V

= 20mV, C

(LT1719S6)

(LT1719S6)

= 10pF and for the LT1719S8

OUT

–

● V

– 0.1 V+ – 1.2 V

● –5.5 1.5 mV

● 3.5 mV

● 55 65 dB

+

● V

– 0.4 V

LT1719

ELECTRICAL CHARACTERISTICS

range, otherwise specifications are at T

= 25°C. V

A

CM

The ● denotes specifications that apply over the full operating temperature

= 1V, V

SHDN

= 0.5V, V

OVERDRIVE

= 20mV, C

= 10pF and for the LT1719S8

OUT

VCC = +VS = 5V and VEE = –5V, for the LT1719S6 V+ = 5V, V– = 0V, unless otherwise specified.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

V

OL

t

PD20

t

PD5

t

SKEW

t

r

t

f

t

JITTER

Output Low Voltage I
Propagation Delay V

Propagation Delay V

= 10mA, VIN = V

SINK

OVERDRIVE

V

OVERDRIVE

OVERDRIVE

= 20mV (Note 9) VEE = 0V(LT1719S8) 4.5 6.5 ns

= 20mV, VEE = –5V (LT1719S8 only) 4.2 ns
= 5mV (Notes 9, 10) VEE = 0V(LT1719S8) 7 10 ns

Propagation Delay Skew (Note 11) 0.5 1.5 ns
Output Rise Time 10% to 90% 2.5 ns
Output Fall Time 90% to 10% 2.2 ns
Output Timing Jitter VIN = 1.2V

(6dBm), ZIN = 50Ω t

P-P

f = 20MHz t

f

MAX

t

OFF

t

ON

I

CC

Maximum Toggle Frequency V

OVERDRIVE

V

OVERDRIVE

Turn-Off Delay Time to Z

= 50mV, +VS or V+ = 3V 70 MHz
= 50mV, +VS or V+ = 5V 62.5 MHz

≥10kΩ 75 ns

OUT

Wake-Up Delay Time to VOH or VOL, I
Positive Input Stage Supply Current +VS = VCC = 5V, VEE = –5V ● 1.0 2.2 mA

(LT1719S8 0nly) +VS = VCC = 3V, VEE = 0V ● 0.9 1.8 mA

I

EE

Negative Input Stage Supply Current + VS = VCC = 5V, VEE = –5V ● –4.8 –2.6 mA

(LT1719S8 0nly) +VS = VCC = 3V, VEE = 0V ● –3.8 –2.2 mA

I

S

Positive Output Stage Supply Current +VS = VCC = 5V, VEE = –5V ● 4.2 8 mA

(LT1719S8 0nly) VS = VCC = 3V, VEE = 0V ● 3.3 6 mA

+

I

Supply Current (LT1719S6) V+ = 5V ● 4.6 9 mA

V+ = 3V ● 4.2 7 mA

I

SHDN5

I

SHDN3

I

CCS

I

SS

I

EES
+

I

S

I

CCSO

I

SSO

I

EEO
+

I

O

Shutdown Pin Current +VS or V+ = 5V ● –300 –110 –30 µA
Shutdown Pin Current +VS or V+ = 3V ● –200 –80 –20 µA
Disabled Supply Currents (LT1719S8) +VS = 6V, VCC = 5V, VEE = –5V ● 0.2 30 µA

(LT1719S8) V

= +VS – 0.5V ● 750 µA

SHDN

(LT1719S8) ● –30 –0.2 µA
(LT1719S6) V+ = 6V, V

= +VS – 0.5V ● 780 µA

SHDN

(LT1719S8) +VS = 6V, VCC = 5V, VEE = –5V ● 0.1 20 µA
(LT1719S8) Shutdown Pin Open ● 0.1 20 µA
(LT1719S8) ● –20 0.1 µA

(LT1719S6) V+ = 6V, Shutdown Pin Open ● 0.2 40 µA

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

–

, while the hysteresis voltage is the difference of these two.

V

TRIP

TRIP

+

and

Note 4: The LT1719S8 common mode rejection ratio is measured with

= 5V, VEE = –5V and is defined as the change in offset voltage

V

CC

measured from V

= –5.1V to VCM = 3.8V, divided by 8.9V.

CM

–

– 10mV ● 0.4 V

TRIP

–

= 0V(LT1719S6) ● 8.0 ns

V

–

= 0V(LT1719S6) ● 13 ns

V

+

PD

–

PD

= 1mA 350 ns

LOAD

15 ps
11 ps

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

= –0.1V to VCM = 3.8V, divided by 3.9V.

CM

Note 6: The LT1719S8 power supply rejection ratio is measured with
V

= 1V and is defined as the worst of: the change in offset voltage

CM

from V
voltage from V

= –5.5V to VEE = 0V divided by 5.5V, or the change in offset

EE

= +VS = 2.7V to VCC = +VS = 6V (with VEE = 0V)

CC

divided by 3.3V.
Note 7: The 1719S6 power supply rejection ratio is measured with

V

= 1V and is defined as the change in offset voltage measured from

CM
+

= 2.7V to V+ = 6V, divided by 3.3V.

V

RMS
RMS

3

LT1719

TEMPERATURE (°C)

–50

0

3.8

4.2

25 75

1719 G03

–0.2

–5.0

–25 0

50 100 125

–5.2

–5.4

4.0

COMMON MODE INPUT VOLTAGE (V)

+VS = VCC OR V+ = 5V

VEE = –5V (LT1719S8)

V

–

= GND (LT1719S6)

SUPPLY VOLTAGE, VCC = +VS OR V+ (V)

0

SUPPLY CURRENTS (mA)

2

6

5

4

3

2

1

0

–1

–2

–3

1719 G06

173456

TA = 25°C
V

EE

= GND

I+ (LT1719S6)

IS (LT1719S8)

ICC (LT1719S8)

IEE (LT1719S8)

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 VOH and VOL 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

with low values of overdrive. The LT1719 is 100% tested with a
100mV step and 20mV overdrive. Correlation tests have shown that

limits can be guaranteed with this test, if additional DC tests are

t

PD

performed to guarantee that all internal bias conditions are correct.
Note 11: Propagation Delay Skew is defined as:

= |t

t

SKEW

W

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TYPICAL PERFORMANCE CHARACTERISTICS

Input Offset and Trip Voltages
vs Supply Voltage

3

V

2

1

0

–1

AND TRIP POINT VOLTAGE (mV)

25°C

–2

OS

V

= 1V

V

CM

OR V– = GND

V

EE

–3

2.5

3.0 3.5

SUPPLY VOLTAGE, VCC = +VS OR V+ (V)

TRIP

V

OS

V

TRIP

4.5 5.5 6.0

4.0 5.0

+

–

1719 G01

Input Offset and Trip Voltages
vs Temperature

3

V

2

1

0

–1

AND TRIP POINT VOLTAGE (mV)

+VS = VCC or V+ = 5V

–2

OS

V

–3

= 1V

V

CM

OR V– = GND

V

EE

–20 20 60 100

TRIP

V

OS

V

TRIP

TEMPERATURE (°C)

+

–

cannot be measured in automatic handling equipment

– t

PDHL

|

PDLH

Input Common Mode Limits
vs Temperature

140–40–60 0 40 80 120

1719 G02

Input Current
vs Differential Input Voltage

2

25°C

1

0

–1

–2

–3

INPUT BIAS (µA)

–4

–5

–6

–7

4

–4 –3 –2 –1 0 5

–5

DIFFERENTIAL INPUT VOLTAGE (V)

1234

1719 G04

Quiescent Supply Current
vs Temperature

10

VCC = +VS OR V+ = 5V
V

= GND

EE

8

6

4

2

0

SUPPLY CURRENT (mA)

–2

–4

–6

–25 25 75 125

–50

050

TEMPERATURE (°C)

Quiescent Supply Current
vs Supply Voltage

I+ (LT1719S6)

+IS (LT1719S8)

ICC (LT1719S8)

IEE (LT1719S8)

100

1339 G05

W

FREQUENCY (MHz)

0

6

8

30

NO LOAD

1719 G12

4

3

10 20 40

2

5

7

9

+V

S

SUPPLY CURRENT (mA)

25°C
+V

S

= 5V

C

LOAD

= 20pF

C

LOAD

= 10pF

SUPPLY VOLTAGE, +VS = VCC OR V+ (V)

2.5

4.0

3.5

PROPAGATION DELAY (ns)

5.5

5.0
t

TPLH

t

TPLH

t

TPHL

t

TPHL

4.5

4.0 5.0

1719 G09

3.0 3.5

4.5 5.5 6.0

25°C
V

STEP

= 100mV
OVERDRIVE = 20mV
C

LOAD

= 10pF

VEE/V–= GND

V

EE

= –5V

(V

CC

, +VS = 5.5V

MAX

)

(LT1719S8 ONLY)

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TYPICAL PERFORMANCE CHARACTERISTICS

LT1719

Propagation Delay
vs Load Capacitance

9

25°C

= 100mV

V

8

STEP

OVERDRIVE = 20mV

7

+V

= VCC OR V+ = 5V

S

OR V– = 0V

V

EE

6

5

4

3

PROPAGATION DELAY (ns)

2

1

0

10 20 40

0

OUTPUT LOAD CAPACITANCE (pF)

Output Low Voltage
vs Load Current

0.5
+VS OR V+ = 5V

= –10mV

V

IN

0.4

0.3

–55°C

OUTPUT VOLTAGE (V)

0.2

0.1

0

V

4

OUTPUT SINK CURRENT (mA)

CC

8

125°C

= 2.7V

RISING EDGE

(t

PDLH

FALLING EDGE

(t

30

125°C

25°C

12

PDHL

16

)

)

1719 G07

1719 G10

Propagation Delay
vs Temperature

8.0
t

PDLH

VCM = 1V

7.5

7.0

6.5

6.0

5.5

5.0

PROPAGATION DELAY (ns)

4.5

50

4.0

= 100mV

V

STEP

OVERDRIVE = 20mV

–25 0 50

–50

OVERDRIVE = 5mV

TEMPERATURE (°C)

C

LOAD

OR V– = GND

V

EE

= VCC = V

+V

S

3V

5V

3V
5V

25

= 10pF

+

75 100 125

1719 G08

Propagation Delay
vs Supply Voltage

Output High Voltage
vs Load Current

0.0

(V)

S

125°C

–0.2

–0.4

–0.6

–0.8

OUTPUT VOLTAGE RELATIVE TO +V

–1.0

20

0

25°C

4

8

OUTPUT SOURCE CURRENT (mA)

–55°C

+VS OR V+= 5V
V

= 10mV

IN

25°C

V

= 2.7V

CC

12

16

20

1719 G11

Supply Current vs Frequency

SUPPLY

SHDN PIN

Shutdown Currents
vs Shutdown Voltage

4

3

LT1719S8

2

CURRENTS (mA)

1

0

TA = 25°C

= GND

V

EE

+V

= VCC = 5V

S

–50

CURRENT (µA)

–100

V

V

–4

S

S

I

S

I

CC

–3 VS –2 VS –1 V
SHDN PIN VOLTAGE (V)

1719 G13a

Shutdown Currents
vs Shutdown Voltage

5

4

+

SUPPLY I

SHDN PIN

S

LT1719S6

3

2

CURRENT (mA)

1

0

TA = 25°C

–50

+

= 5V

V

CURRENT (µA)

–100

+

–4

V

+

V

–3 V+ –2 V+ –1 V+
SHDN PIN VOLTAGE (V)

1719 G13b

5

LT1719

W

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TYPICAL PERFORMANCE CHARACTERISTICS

Shutdown Currents
vs Temperature

10

1

SHUTDOWN CURRENTS (µA)

0.1

–50 25 50 75 100 125–25 0

SHUTDOWN = +V

SHUTDOWN PIN OPEN

– 0.5V

S

TEMPERATURE (°C)

+I

S

SHUTDOWN

PIN

CURRENT

+I

S

VCC = +VS = 5V

= –5V

V

EE

1719 G14

150

UUU

PIN FUNCTIONS

LT1719S8

VCC (Pin 1): Positive Supply Voltage for Input Stage.
+ IN (Pin 2): Noninverting Input of Comparator.

Wake-Up Delay
vs Temperature

700

600

500

400

300

WAKE-UP DELAY (ns)

200

100

–50

–25 0

TEMPERATURE (°C)

50 100 125

25 75

1719 G15

LT1719S6

– IN (Pin 1): Inverting Input of Comparator.

–

V

(Pin 2): Negative Supply, usually Grounded.

– IN (Pin 3): Inverting Input of Comparator.

VEE (Pin 4): Negative Supply Voltage for Input Stage and

Chip Substrate.

GND (Pin 5): Ground.
SHDN (Pin 6): Shutdown. Pull to ground to enable

comparator.

OUT (Pin 7): Output of Comparator.

+VS (Pin 8): Positive Supply Voltage for Output Stage.

+ IN (Pin3): Noninverting Input of Comparator.

V+ (Pin 4): Positive Supply Voltage.
OUT (Pin 5): Output of Comparator.
SHDN (Pin 6): Shutdown. Pull to ground to enable

comparator.

6