LT6700HS6-2#PBF_技术文档

LT6700-1/LT6700-2/LT6700-3

Micropower, Low Voltage,

SOT-23, Dual Comparator

with 400mV Reference

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FEATURES

DESCRIPTIO

■

Low Quiescent Current: 6.5µA Typ at 5V

The LT^®6700-1/LT6700-2/LT6700-3 combine two mi-

cropower, low voltage comparators with a 400mV refer-

enceinthe6-leadSOT-23package.Operatingwithsupplies

from 1.4V up to 18V, the devices draw only 6.5µA typical,

making them ideal for low voltage system monitoring.

Hysteresis is included in the comparators, easing design

requirements to insure stable output operation.

■

Wide Supply Range: 1.4V to 18V

■

400mV Reference ±2% Accuracy Over Temperature

■

Input Range Includes Ground

Over-The-Top^®Input Range

■

Over-The-Top Open-Collector Outputs

■

Internal Hysteresis: 6.5mV Typ

■

Low Input Bias Current: ±10nA Max

The comparators each have one input available externally,

the other inputs are connected internally to the reference.

The comparator outputs are open collector and the output

load can be referred to any voltage up to 18V, independent

of supply voltage. The output stage sinking capability is

guaranteed greater than 5mA over temperature.

■

40mA Typical Output Sink Current

■

Supports Wired-AND Connections

■

Choice of Input Polarities: LT6700-1/LT6700-2/

LT6700-3

Low Profile (1mm) SOT-23 (ThinSOT^TM) Package

■

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The three versions of the part differ by the polarity of the

available comparator inputs. The LT6700-1 has one in-

verting input and one noninverting input, making it suit-

able for use as a window comparator. The LT6700-2 has

two inverting inputs and the LT6700-3 has two noninvert-

ing inputs. All versions are offered in commercial, indus-

trial and automotive temperature ranges.

APPLICATIO S

■

Battery-Powered System Monitoring

Threshold Detectors

Window Comparators

■

Relay Driving

■

Optoisolator Driving

■

, LTC and LT are registered trademarks of Linear Technology Corporation.

Over-The-Top is a registered trademark of Linear Technology.

ThinSOT is a trademark of Linear Technology Corporation.

Industrial Control Systems

■

Handheld Instruments

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TYPICAL APPLICATIO

Micropower Battery Monitor

V

BATT

1.4V (MIN)

3V (NOM)

Comparator Thresholds

5

vs Temperature

LT6700-3

1M

406

#1A

#1B

#2A

#2B

4

COMP B

404

402

400

398

396

394

392

390

+

RISING INPUT

6

V

> 1.6V

BATT

–

63.4k

+

ALKALINE

AA CELLS

V

S

V

R

= 400mV

REFERENCE

FALLING INPUT

COMP A

–

+

TWO TYPICAL PARTS

COMP A AND B

1

V

BATT

> 2V

V

S

= 5V

3

MONITOR CONSUMES ~10µA

HYSTERESIS IS APPROXIMATELY

2% OF TRIP VOLTAGE

–60 –40 –20

0

20 40 60 80 100 120

0.1µF

261k

TEMPERATURE (°C)

2

6700123 TA02

6700123 TA01

6700123fb

1

LT6700-1/LT6700-2/LT6700-3

W W U W

ABSOLUTE AXI U RATI GS ^{(Note 1)}

Total Supply Voltage (V_Sto GND)........................ 18.5V

Input Voltage (+IN, –IN)

(Note 3) ..................................... 18.5V to (GND – 0.3V)

Output Voltage (OUT) ................ 18.5V to (GND – 0.3V)

Output Short-Circuit Duration (Note 2)........... Indefinite

Input Current (Note 3) ....................................... –10mA

Operating Temperature Range (Note 4)

Specified Temperature Range (Note 5)

LT6700CS6-1/-2/-3 ............................ –40°C to 85°C

LT6700IS6-1/-2/-3 ............................. –40°C to 85°C

LT6700HS6-1/-2/-3 .......................... –40°C to 125°C

Maximum Junction Temperature ......................... 150°C

Storage Temperature Range ................... –65°C to 150°

Lead Temperature (Soldering, 10 sec).................. 300°C

LT6700CS6-1/-2/-3 ............................ –40°C to 85°C

LT6700IS6-1/-2/-3 ............................. –40°C to 85°C

LT6700HS6-1/-2/-3 .......................... –40°C to 125°C

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PACKAGE/ORDER I FOR ATIO

TOP VIEW

OUTA 1

GND 2

+INA 3

6 OUTB

5 V

OUTA 1

GND 2

–INA 3

6 OUTB

5 V

OUTA 1

GND 2

+INA 3

6 OUTB

5 V

S

4 –INB

4 +INB

S6 PACKAGE

6-LEAD PLASTIC TSOT-23

S6 PACKAGE

6-LEAD PLASTIC TSOT-23

S6 PACKAGE

6-LEAD PLASTIC TSOT-23

T_JMAX= 150°C, θ_JA= 230°C/W

ORDER PART

NUMBER

S6 PART

MARKING*

ORDER PART

NUMBER

S6 PART

MARKING*

ORDER PART

NUMBER

S6 PART

MARKING*

LT6700CS6-1

LT6700IS6-1

LT6700HS6-1

LTK7

LT6700CS6-2

LT6700IS6-2

LT6700HS6-2

LTADL

LT6700CS6-3

LT6700IS6-3

LT6700HS6-3

LTADM

*The temperature grades are identified by a label on the shipping container. Consult LTC Marketing for parts specified with wider operating temperature ranges.

ELECTRICAL CHARACTERISTICS

T_A= 25°C, unless otherwise specified.

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

V

Rising Input Threshold Voltage

R = 100k, V = 2V Swing

TH(R)

L

O

V = 1.4V

394

395

393

392

400

406

405

407

408

mV

S

V = 5V

S

V = 12V

S

V = 18V

S

V

Falling Input Threshold Voltage

R = 100k, V = 2V Swing

L O

TH(F)

V = 1.4V

386

387

385

384

393.5

401

400

402

403

mV

S

V = 5V

S

V = 12V

S

V = 18V

S

HYS

HYS = V

– V

V = 1.4V, 5V, 12V, 18V, R = 100k, V = 2V Swing

3.5

6.5

9.5

mV

TH(R)

TH(F)

S

L

O

6700123fb

2

LT6700-1/LT6700-2/LT6700-3

ELECTRICAL CHARACTERISTICS

T_A= 25°C, unless otherwise specified.

CONDITIONS

V = 1.4V, 18V, V = V

SYMBOL

PARAMETER

MIN

TYP

MAX

UNITS

I

Input Bias Current

±0.01

±4

±10

nA

B

S

IN

S

V = 1.4V, V = 18V

S

IN

V = 1.4V, 18V, V = 0.1V

S

IN

V

Output Low Voltage

10mV Input Overdrive

OL

V = 1.4V, I

V = 1.6V, I

S

= 0.5mA

= 3mA

55

60

70

200

mV

S

OUT

V = 5V, I

= 5mA

S

OUT

I

t

I

Output Leakage Current

High-to-Low Propagation Delay

Low-to-High Propagation Delay

Output Rise Time

V = 1.4V, 18V, V

= V , V = 40mV Overdrive

0.01

0.8

µA

OFF

S

OUT

S

IN

V = 1.4V, V

S

= 18V, V = 40mV Overdrive

OUT

IN

V = 5V, 10mV Input Overdrive, R = 10k,

29

µs

PD(HL)

S

L

V

= 400mV

OL

V = 5V, 10mV Input Overdrive, R = 10k,

18

PD(LH)

S

L

V

= 0.9 • V

OH

S

V = 5V, 10mV Input Overdrive, R = 10k

2.2

0.22

r

S

L

V = (0.1 to 0.9) • V

O

S

Output Fall Time

V = 5V, 10mV Input Overdrive, R = 10k

S L

V = (0.1 to 0.9) • V

O

f

S

Supply Current

No Load Current

S

V = 1.4V

5.7

6.5

6.9

7.1

10.0

11.0

12.5

13.0

µA

S

V = 5V

S

V = 12V

S

V = 18V

S

The ● denotes the specifications which apply over the temperature range of 0°C ≤ T_A≤ 70°C, unless otherwise specified (Notes 4, 5).

SYMBOL

PARAMETER

CONDITIONS

R = 100k, V = 2V Swing

MIN

TYP

MAX

UNITS

V

Rising Input Threshold Voltage

TH(R)

L

O

V = 1.4V

●

391.0

392.5

390.0

389.0

409.0

407.5

410.0

411.0

mV

S

V = 5V

S

V = 12V

S

V = 18V

S

V

Falling Input Threshold Voltage

R = 100k, V = 2V Swing

L O

TH(F)

V = 1.4V

●

383.5

384.5

382.5

381.5

403.5

402.5

404.5

405.5

mV

S

V = 5V

S

V = 12V

S

V = 18V

S

HYS

HYS = V

– V

V = 1.4V, 5V, 12V, 18V, R = 100k, V = 2V Swing

●

3

11

mV

TH(R)

TH(F)

S

L

O

I

Input Bias Current

V = 1.4V, 18V, V = V

S

●

±15

nA

B

S

IN

V = 1.4V, V = 18V

S

IN

V = 1.4V, 18V, V = 0.1V

S

IN

V

Output Low Voltage

10mV Input Overdrive

OL

V = 1.4V, I

V = 1.6V, I

S

= 0.5mA

= 3mA

●

250

mV

S

OUT

V = 5V, I

= 5mA

S

OUT

I

Output Leakage Current

Supply Current

V = 1.4V, 18V, V

= V , V = 40mV Overdrive

●

1

µA

OFF

S

OUT

S

IN

V = 1.4V, V

S

= 18V, V = 40mV Overdrive

OUT

IN

No Load Current

V = 1.4V

●

13.0

14.0

15.5

16.0

µA

S

V = 5V

S

V = 12V

S

V = 18V

S

6700123fb

3

LT6700-1/LT6700-2/LT6700-3

ELECTRICAL CHARACTERISTICS

The ● denotes the specifications which apply over the temperature range of

–40°C ≤ T_A≤ 85°C, unless otherwise specified (Notes 4, 5).

SYMBOL

PARAMETER

CONDITIONS

R = 100k, V = 2V Swing

MIN

TYP

MAX

UNITS

V

TH(R)

Rising Input Threshold Voltage

L

O

V = 1.4V

●

390

392

389

388

410

408

411

412

mV

S

V = 5V

S

V = 12V

S

V = 18V

S

V

TH(F)

Falling Input Threshold Voltage

R = 100k, V = 2V Swing

L O

V = 1.4V

●

382.5

383.5

381.5

380.5

404.5

403.5

405.5

406.5

mV

S

V = 5V

S

V = 12V

S

V = 18V

S

HYS

HYS = V

– V

V = 1.4V, 5V, 12V, 18V, R = 100k, V = 2V Swing

●

2

11.5

mV

TH(R)

TH(F)

S

L

O

I

Input Bias Current

V = 1.4V, 18V, V = V

S

●

±15

nA

B

S

IN

V = 1.4V, V = 18V

S

IN

V = 1.4V, 18V, V = 0.1V

S

IN

V

OL

Output Low Voltage

10mV Input Overdrive

V = 1.4V, I

= 0.1mA

= 3mA

●

250

mV

S

OUT

V = 1.6V, I

V = 5V, I

= 5mA

S

OUT

I

Output Leakage Current

Supply Current

V = 1.4V, 18V, V

= V , V = 40mV Overdrive

●

1

µA

OFF

S

OUT

S

IN

V = 1.4V, V

= 18V, V = 40mV Overdrive

IN

S

OUT

No Load Current

V = 1.4V

●

14.0

15.0

16.5

17.0

µA

S

V = 5V

S

V = 12V

S

V = 18V

S

The ● denotes the specifications which apply over the temperature range of –40°C ≤ T_A≤ 125°C, unless otherwise specified (Notes 4, 5).

LT6700H

TYP

SYMBOL

PARAMETER

CONDITIONS

R = 100k, V = 2V Swing

MIN

MAX

UNITS

V

Rising Input Threshold Voltage

TH(R)

L

O

V = 1.4V

●

390

392

389

388

411

410

412

413

mV

S

V = 5V

S

V = 12V

S

V = 18V

S

V

Falling Input Threshold Voltage

R = 100k, V = 2V Swing

L O

TH(F)

V = 1.4V

●

381.5

382.5

380.5

379.5

405.5

404.5

406.5

407.5

mV

S

V = 5V

S

V = 12V

S

V = 18V

S

HYS

HYS = V

– V

V = 1.4V, 5V, 12V, 18V, R = 100k, V = 2V Swing

●

2

13.5

mV

TH(R)

TH(F)

S

L

O

I

Input Bias Current

V = 1.4V, 18V, V = V

S

●

±45

±50

nA

B

S

IN

V = 1.4V, V = 18V

S

IN

V = 1.4V, 18V, V = 100mV

S

IN

V

Output Low Voltage

10mV Input Overdrive

OL

V = 1.4V, I

= 0.1mA

= 3mA

●

250

mV

S

OUT

V = 1.6V, I

V = 5V, I

= 5mA

S

OUT

I

Output Leakage Current

Supply Current

V = 1.4V, 18V, V

= V , V = 40mV Overdrive

●

1

µA

OFF

S

OUT

S

IN

V = 1.4V, V

= V , V = 40mV Overdrive

S IN

S

OUT

No Load Current

V = 1.4V

●

16.0

17.0

18.5

19.0

µA

S

V = 5V

S

V = 12V

S

V = 18V

S

6700123fb

4

LT6700-1/LT6700-2/LT6700-3

ELECTRICAL CHARACTERISTICS

Note 1: Absolute Maximum Ratings are those beyond which the life of the

device may be impaired.

LT6700HS6-1/-2/-3 are guaranteed functional over the operating

temperature range of –40°C to 125°C.

Note 2: A heat sink may be required to keep the junction temperature

below the absolute maximum rating when the output is shorted

indefinitely.

Note 3: The inputs are protected by ESD diodes to the ground. If the input

voltage exceeds –0.3V below ground, the input current should be limited

to less than 10mA.

Note 5: The LT6700CS6-1/-2/-3 are guaranteed to meet the specified

performance from 0°C to 70°C. The LT6700CS6-1/-2/-3 are designed,

characterized and expected to meet specified performance from –40°C to

85°C but are not tested or QA sampled at these temperatures. The

LT6700IS6-1/-2/-3 are guaranteed to meet specified performance from

–40°C to 85°C. The LT6700HS6-1/-2/-3 are guaranteed to meet specified

performance from –40°C to 125°C.

Note 4: The LT6700CS6-1/-2/-3 and LT6700IS6-1/-2/-3 are guaranteed

functional over the operating temperature range of –40°C to 85°C. The

U

PI FU CTIO S

V

S

V

S

5

LT6700-3

LT6700-1

LT6700-2

COMP B

+INB

4

+

–

–INB

4

–INB

4

–

+

–

6

OUTB

6

OUTB

6

OUTB

+

V

S

V

S

V

S

400mV

REFERENCE

400mV

REFERENCE

400mV

REFERENCE

COMP A

+

–

1

OUTA

1

OUTA

+

+INA

3

+INA

3

–INA

3

–

6700123 PF03

6700123 PF01

6700123 PF02

2

GND

OUTA (Pin 1): Open-Collector Output of Comparator Sec-

tion A. This pin provides drive for up to 40mA of load

current. Off-state voltage may be as high as 18V above

GND (Pin 2), regardless of V_Sused.

INB (Pin 4): External Input for Comparator Section B. The

voltage on this pin can range from –0.3V to 18V with

respect to GND (Pin 2) regardless of V_Sused. The input is

noninverting for the LT6700-3, and inverting for the

LT6700-1 and LT6700-2. The other section B comparator

input is internally connected to the 400mV reference.

GND (Pin 2): Ground. This pin is also the low side return

of the internal 400mV reference.

V_S(Pin5):ComparatorCoreSupplyVoltage. Thepartsare

characterized for operation with 1.4V ≤ V_S≤ 18V with

respect to GND (Pin 2).

INA (Pin 3): External Input for Comparator Section A. The

voltage on this pin can range from –0.3V to 18V with

respect to GND (Pin 2) regardless of V_Sused. The input is

noninverting for the LT6700-1 and LT6700-3, and invert-

ing for the LT6700-2. The other section A comparator

input is internally connected to the 400mV reference.

OUTB (Pin 6): Open-Collector Output of Comparator Sec-

tion B. This pin provides drive for up to 40mA of load

current. Off-state voltage may be as high as 18V above

GND (Pin 2), regardless of V_Sused.

6700123fb

5

LT6700-1/LT6700-2/LT6700-3

U W

TYPICAL PERFOR A CE CHARACTERISTICS

Distribution of Rising Input

Threshold Voltage

Distribution of Falling Input

Threshold Voltage

Distribution of Hysteresis

18

16

14

12

10

8

20

18

16

14

12

10

8

18

16

14

12

10

8

V

S

T

= 5V

= 25°C

V

= 5V

S

V

T

= 5V

= 25°C

S

T

= 25°C

A

6

4

2

0

394

396

398

400

402

404

406

388

390

392

394

396

398

400

4

4.8

5.6

6.4

7.2

8

8.8

RISING INPUT THRESHOLD VOLTAGE (mV)

FALLING INPUT THRESHOLD VOLTAGE (mV)

HYSTERESIS (mV)

6700123 G01

6700123 G02

6700123 G03

Rising Input Threshold Voltage

vs Temperature

Rising Input Threshold Voltage

vs Temperature

Rising Input Threshold Voltage

vs Supply Voltage

404

403

402

401

400

399

398

397

396

403.0

402.5

402.0

401.5

401.0

400.5

400.0

399.5

399.0

403.0

402.5

402.0

401.5

401.0

400.5

400.0

399.5

399.0

V

= 1.4V

= 5V

= 12V

= 18V

T

A

T

A

T

A

T

A

= 25°C

= 85°C

= 125°C

= –55°C

FOUR TYPICAL PARTS

S

V

= 5V

#1

#2

#3

#4

0

20 40 60 80

0

20 40 60 80

8

10 12

–60 –40 –20

100 120

–60 –40 –20

100 120

2

4

6

14 16 18

TEMPERATURE (°C)

SUPPLY VOLTAGE (V)

6700123 G04

6700123 G05

6700123 G06

Hysteresis vs Temperature

Hysteresis vs Supply Voltage

10

9

10

9

10

9

T

A

T

A

= 25°C

= 85°C

T

= 125°C

= –55°C

V

S

V

S

V

S

V

S

= 1.4V

= 5V

= 12V

= 18V

FOUR TYPICAL PARTS

S

A

V

= 5V

#1

#2

#3

#4

8

7

6

5

4

3

2

0

20 40 60 80

0

20 40 60 80

8

10 12

–60 –40 –20

100 120

–60 –40 –20

100 120

2

4

6

14 16 18

TEMPERATURE (°C)

SUPPLY VOLTAGE (V)

6700123 G07

6700123 G08

6700123 G09

6700123fb

6

LT6700-1/LT6700-2/LT6700-3

U W

TYPICAL PERFOR A CE CHARACTERISTICS

Quiescent Supply Current

vs Supply Voltage

Minimum Supply Voltage

Start-Up Supply Current

1

0

50

40

30

20

10

0

10

9

T

= 25°C

= 85°C

T

= 125°C

= –55°C

T

= 25°C

= 85°C

= 125°C

= –55°C

A

NO LOAD CURRENT

–1

–2

–3

–4

–5

8

7

6

T

= 25°C

= 85°C

= 125°C

= –55°C

A

T

5

4

0.9

1.1

1.3

1.5

1.7

1.9

0

0.2 0.4 0.6 0.8 1.0 1.2 1.4

SUPPLY VOLTAGE (V)

6700123 G12

7.4 9.4 11.4

1.4 3.4 5.4

13.4 15.4 17.4

SUPPLY VOLTAGE (V)

6700123 G10

6700123 G11

Supply Current

vs Output Sink Current

Supply Current

vs Output Sink Current

Supply Current

vs Output Sink Current

1000

100

10

1000

100

10

1000

100

10

T

= –40°C

T

= 25°C

T

= 85°C

A

V

= 1.4V

V

= 1.4V

= 5V

= 12V

= 18V

V

= 1.4V

= 5V

= 12V

= 18V

S

= 5V

= 12V

= 18V

V

S

1

0.001

0.01

0.1

1

10

100

0.001

0.01

0.1

1

10

100

0.001

0.01

0.1

1

10

100

OUTPUT SINK CURRENT (mA)

6700123 G13

6700123 G14

6700123 G15

Below Ground Input Bias Current

Low Level Input Bias Current

High Level Input Bias Current

3

2

10000

1000

100

10

1

V

= 18V

CURRENT IS POSITIVE GOING

INTO THE DEVICE

S

CURRENT IS GOING INTO THE DEVICE

–0.3V < V < 0V

IB

T

= 25°C

= 85°C

= 125°C

= –55°C

A

1

0

–1

–2

–3

–4

–5

–6

–7

0.1

V

= 18V

IB

S

0V < V < 1V

V

= 18V

> 1V

S

IB

T

A

T

A

T

A

T

A

= 25°C

= 85°C

= 125°C

= –55°C

0.01

0.001

T

= 25°C

= 85°C

= 125°C

A

CURRENT IS GOING OUT OF THE DEVICE

–0.2 –0.1

INPUT VOLTAGE (V)

1

0.5 0.8 0.9

0.6 0.7

1

0

0.4

–0.3

0

0.1 0.2 0.3

1

3

5

7

9

11 13 15 17

INPUT VOLTAGE (V)

6700123 G16

6700123 G18

6700123 G17

6700123fb

7

LT6700-1/LT6700-2/LT6700-3

U W

TYPICAL PERFOR A CE CHARACTERISTICS

Output Saturation Voltage

vs Output Sink Current

Output Saturation Voltage

vs Output Sink Current

Output Saturation Voltage

vs Output Sink Current

1000

100

10

1000

100

10

1000

100

10

T

= –40°C

T

= 25°C

T

= 85°C

A

V

= 1.4V

V

= 1.4V

= 5V

V

= 1.4V

= 5V

S

= 5V

= 12V

= 18V

V

S

= 12V

= 18V

= 12V

= 18V

1

0.001

0.01

0.1

1

10

100

0.001

0.01

0.1

1

10

100

0.001

0.01

0.1

1

10

100

OUTPUT SINK CURRENT (mA)

6700123 G19

6700123 G20

6700123 G21

Output Short-Circuit Current

Output Leakage Current

10

1

80

70

60

50

40

30

20

10

0

80

70

60

50

40

30

20

10

0

T

A

= 25°C

V

S

V

S

V

S

V

S

= 1.4V

= 5V

= 12V

= 18V

0.1

0.01

V

= 5V

S

T

= 25°C

= 85°C

= 125°C

= –55°C

A

T

V

S

= 5V

T

= 25°C

= 85°C

= 125°C

= –55°C

A

T

0.001

8

10 12

8

10 12

0

2

4

6

14 16 18

0

2

4

6

14 16 18

0

2

4

6

8

10 12 14 16 18

OUTPUT VOLTAGE (V)

6700123 G24

6700123 G22

6700123 G23

Propagation Delay

vs Input Overdrive

Rise and Fall Times

vs Output Pull-Up Resistor

Noninverting and Inverting

Comparators’ Propagation Delay

100

10

60

50

40

30

20

10

0

V

C

T

= 5V

= 20pF

= 25°C

LH NONINV

HL NONINV

LH INV

S

L

A

T

= 25°C

A

V_O(NINV)

5V/DIV

DC

V_O(INV)

5V/DIV

DC

HL INV

RISE

FALL

1

V_IN

10mV/DIV

AC

0.1

0.01

V_S= 5V

T_A= 25°C

20µs/DIV

67000123 G27

R_LOAD= 10k CONNECTED TO VS

V_{IN(OVERDRIVE)}= 10mV OVER THE INPUT

VOLTAGE THRESHOLDS

0.1

1

10

100

1000

0

20

40

60

80

100

OUTPUT PULL-UP RESISTOR (kΩ)

INPUT OVERDRIVE (mV)

6700123 G26

6700123 G25

6700123fb

8

LT6700-1/LT6700-2/LT6700-3

W U U

APPLICATIO S I FOR ATIO

U

TheLT6700-1/LT6700-2/LT6700-3devicesareafamilyof

dual micropower comparators with a built-in 400mV ref-

erence. Features include wide supply voltage range (1.4V

to 18V), Over-The-Top input and output range, 2% accu-

raterisinginputthreshold voltage and 6.5mVtypicalbuilt-

in hysteresis. The comparator’s open-collector outputs

can sink up to 40mA typical.

(providedthecurrentislimitedto10mA), buttheaccuracy

of the reference cannot be guaranteed, in which case the

output state of the alternate comparator may be effected.

Comparator Outputs

The comparator outputs are open collector and capable of

sinking 40mA typical. Load currents are directed out the

GNDpinofthepart.Theoutputoff-statevoltagemayrange

between–0.3Vand18Vwithrespecttoground,regardless

of the supply voltage used. As with any open-collector

device, the outputs may be tied together to implement

wire-AND logic functions.

Internal Reference

Each of the comparator sections has one input available

externally, with the three versions of the part differing by

the polarity of those available inputs (i.e., inverting or

noninverting).Theothercomparatorinputsareconnected

internally to the 400mV reference. The rising input thresh-

old voltage of the comparators is designed to be equal to

thatofthereference(i.e., ≈400mV). Thereferencevoltage

is established with respect to the device GND connection.

Power Supplies

The comparator family core circuitry operates from a

single 1.4V to 18V supply. A minimum 0.1µF bypass

capacitor is required between the V_Spin and GND. When

an output load is connected to the supply rail near the part

and the output is sinking more than 5mA, a 1µF bypass

capacitor is recommended. In instances where the supply

is relatively “soft” (such as with small batteries) and

susceptible to load steps, an additional 47Ω series de-

coupling resistor can further improve isolation of supply

transients from the V_Spin.

Hysteresis

Eachcomparatorhasbuilt-in6.5mV(typical)hysteresisto

simplify designs, insure stable operation in the presence

of noise at the inputs, and to reject supply rail noise that

might be induced by state change load transients. The

hysteresisisdesignedsuchthatthefallinginputthreshold

voltage is nominally 393.5mV. External positive feedback

circuitry can be employed with noninverting comparator

inputs to increase effective hysteresis if desired, but such

circuitry will provide an apparent effect on both the rising

and falling input thresholds (the actual internal thresholds

remain unaffected).

Flexible Window Comparator

Using the LT6700-1 as shown in the circuits of Figure 1,

the wire-AND configuration permits high accuracy win-

dow functions to be implemented with a simple 3-resistor

voltage divider network. The section A comparator pro-

vides the V_Ltrip-point and the section B comparator

provides the V_Htrip-point, with the built-in hysteresis

providing about 1.7% recovery level at each trip point to

prevent output chatter.

Comparator Inputs

A comparator input can swing from ground to 18V,

regardless of the supply voltage used. The typical input

current for inputs well above threshold (i.e., >800mV) is

a few pA leaking into an input. With decreasing input

voltage, a small bias current begins to be drawn out of the

input, reaching a few nA when at ground potential. The

inputmaybeforced100mVbelowgroundwithoutcausing

an improper output, though some additional bias current

will begin to flow from the parasitic ESD input protection

diode. Inputs driven further negative than 100mV below

ground will not cause comparator malfunction or damage

For designs that are to be optimized to detect departure

from a window limit, the nominal resistor divider values

are selected as follows (refer to the resistor designators

shown on the first circuit of Figure 1):

R1 ≤ 400k (this sets the divider current >> I_Bof inputs)

R2 = R1 • (0.98 • V_H/V_L– 1)

R3 = R1 • (2.5 • V_H– 0.98 • V_H/V_L)

6700123fb

9

LT6700-1/LT6700-2/LT6700-3

W U U

U

APPLICATIO S I FOR ATIO

3.3V Supply Monitor

5V Supply Monitor

3.3V

5V

V

H

L

V

R3

5

OUT

5

487k

301k

V

S

3

4

1

6

3

4

1

6

33k

+INA OUTA

LT6700-1

R2

6.04k

V

S

LT6700-1

6.04k

40.2k

V

OUT

–INB OUTB

GND

–INB OUTB

GND

HIGH = (3.1V < V < 3.5V)

S

HIGH = (4.7V < V < 5.3V)

S

R1

40.2k

0.1µF

2

HYSTERESIS ZONES

APPROXIMATELY

2% OF TRIP VOLTAGE

6700123 F01

Figure 1. Simple Window Comparator

0.1µF

To create window functions optimized for detecting entry

into a window (i.e. where the output is to indicate a

“coming into spec” condition, as with the examples in

Figure 1), the nominal resistor values are selected as

follows:

1.4V TO 18V

(I ≈ 10µA)

2 • V

S

REF

5

R

499k

220k 220k*

T < T

SET

V

S

3

4

1

6

+INA OUTA

LT6700-1

SET

10k

–INB OUTB

GND

R1 ≤ 400k (this sets the divider current >> I_Bof inputs)

R2 = R1 • (1.02 • V_H/V_L– 1)

R

TH

3.3µF

T

2

6700123 F02

R3 = R1 • (2.54 • V_H– 1.02 • V_H/V_L)

R

= 1M (e.g., YSI 44015, 1.00MΩ AT 25°C)

TH

= R AT T

SET

TH

SET

The worst-case variance of the trip-points is related to the

specified threshold limits of the LT6700 device and the

basic tolerance of divider resistors used. For resistor

tolerance R_TOL(e.g. 0.01 for 1%), the worst-case trip-

point voltage (either V_Hor V_L) deviations can be predicted

as follows (italicized values are taken from the datasheet,

expressed in volts):

*RESISTANCE MAY REQUIRE OPTIMIZATION FOR OPERATION

OVER INTENDED R AND V

HYSTERESIS ZONE ≈0.4°C

RANGES

TH

SUPPLY

Figure 2. Micropower Thermostat/Temperature Alarm

been doubled to drive a resistor bridge. The section B

output cycles on and off to swing the section B input

between its hysteresis trip points as the load capacitor

charges and discharges in a shallow, controlled fashion.

The multiplied reference signal also contains ripple that is

the hysteresis multiplied by the same factor, so additional

filtering is performed at the sense node of the bridge to

prevent comparator chatter in the section A comparator,

which is performing the actual conditional decision for the

circuit.

Max dev V_TRIP↑= ±V_TRIPnom• {2 • R_TOL• [(V_TRIPnom– 0.4)

/ V_TRIPnom] + 1.25 • (V_TH(R)max– V_TH(R)min)}

Max dev V_TRIP↓= ±V_TRIPnom• {2 • R_TOL• [(V_TRIPnom– 0.39)

/ V_TRIPnom] + 1.27 • (V_TH(F)max– V_TH(F)min)}

Generating an External Reference Signal

In some applications, it would be advantageous to have

access to a signal that is directly related to the internal

400mV reference, even though the reference itself is not

availableexternally.Thiscanbeaccomplishedtoareason-

able degree by using an inverting comparator section as a

“bang-bang” servo, establishing a nominal voltage, on an

integration capacitor, that is scaled to the reference. This

method is used in Figure 2, where the reference level has

Instrumentation Grade Pulse Width Modulator (PWM)

Comparators with hysteresis are frequently employed to

make simple oscillator structures, and the LT6700 lends

itself nicely to forming a charge-balancing PWM function.

ThecircuitshowninFigure3formsaPWMthatisintended

to transmit an isolated representation of a voltage differ-

6700123fb

10

LT6700-1/LT6700-2/LT6700-3

W U U

APPLICATIO S I FOR ATIO

U

ence, ratherlikeanisolatedinstrumentationamplifier. The

section B comparator is used to generate a 2V reference

supply level for the CMOS NOT gate (inverter), which

serves as the precision switch element for the charge

balancer. The heart of the charge balancer is the section A

comparator, which is detecting slight charge or discharge

states on the 0.22µF “integration” capacitor as it remains

balanced at ≈400mV by feedback through the NOT gate.

The input sense voltage, V_IN, is converted to an imbalance

current that the NOT gate duty cycle is continually correct-

ing for, thus the digital waveform at the section A com-

paratoroutputisaPWMrepresentationofV_INwithrespect

to the 2V “full scale.” In this particular circuit, the PWM

informationdrivestheLEDofanoptocoupler, allowingthe

V_INinformation to be coupled across a dielectric barrier.

Asanadditionaloptiontothecircuit,thefeedbackloopcan

be broken and a second optocoupler employed to provide

the charge balance management. This configuration al-

lows for clocking the comparator output (externally to this

circuit) and providing synchronous feedback such that a

simple∆Σvoltage-to-frequencyconversioncanbeformed

if desired. Approximately 11-bit accuracy and noise per-

formancewasobservedinaonesecondintegrationperiod

for duty factors from 1% to 99%.

W U U

U

APPLICATIO S I FOR ATIO

3V/5V

3V NOM (I < 3mA)

S

10k

+

Lithium

COIN CELL

0.1µF

750Ω

PWM OUT

10k**

(OR ∆Σ SENSE)

1

2

6

470Ω

5 • V

= 2V

REF

MOC-207

5

22µF

412k*

10k 10k

V

NC7S14

309k*

S

309k*

††

3

1

5

+INA OUTA

LT6700-1

10k

6

3V/5V

750**

4

†

+

–INB OUTB

GND

V

IN

0.22µF

0.1µF

100k* 100k*

0V TO 2V

2

6

1

–

MOC-207**

6700123 F03

*1% METAL FILM

5

2

**DELETE FOR PWM MODE

†

∆Σ

SAMPLE

IN

CONNECT FOR PWM MODE

††

OPTIMIZED FOR 2kHz ∆Σ SAMPLING, f

≈ 0.6kHz

PWM(MAX)

Figure 3. Isolated PWM or ∆Σ Converter

6700123fb

Information furnished by Linear Technology Corporation is believed to be accurate and reliable.

However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-

tationthattheinterconnectionofitscircuitsasdescribedhereinwillnotinfringeonexistingpatentrights.

11

LT6700-1/LT6700-2/LT6700-3

U

PACKAGE DESCRIPTIO

S6 Package

6-Lead Plastic TSOT-23

(Reference LTC DWG # 05-08-1636)

2.90 BSC

(NOTE 4)

0.62

MAX

0.95

REF

1.22 REF

1.4 MIN

NOTE:

1. DIMENSIONS ARE IN MILLIMETERS

2. DRAWING NOT TO SCALE

3. DIMENSIONS ARE INCLUSIVE OF PLATING

4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH

AND METAL BURR

1.50 – 1.75

(NOTE 4)

2.80 BSC

3.85 MAX 2.62 REF

5. MOLD FLASH SHALL NOT EXCEED 0.254mm

6. JEDEC PACKAGE REFERENCE IS MO-193

PIN ONE ID

RECOMMENDED SOLDER PAD LAYOUT

PER IPC CALCULATOR

0.30 – 0.45

6 PLCS (NOTE 3)

0.95 BSC

0.80 – 0.90

0.20 BSC

DATUM ‘A’

0.01 – 0.10

1.00 MAX

0.30 – 0.50 REF

1.90 BSC

0.09 – 0.20

(NOTE 3)

S6 TSOT-23 0302

U

TYPICAL APPLICATIO S

PowerPath^TMController

48V Status Monitor

B0520LW

+

V

SUPPLY

“WART” INPUT

1.6V MIN

3V NOM

33k

22V

CMPZ5251B

3.3V NOM

Si2301DS

1.74M

7.87k

5

10k

V

H

V

L

3V/5V

V

S

LED OFF

3

4

1

6

+INA OUTA

V

OUT

V

1k

100k

LT6700-1

27k

33k

IN

V

OUT

LOW = (39V < V < 70V)

1M

R2

1M

R1

–INB OUTB

GND

LED ON

IN

1

6

V

IN

+

5

2

HYSTERESIS ZONES

APPROXIMATELY

2% OF TRIP VOLTAGE

ALKALINE

AA CELLS

0.1µF

V

S

MOC-207

3

4

1

6

10k

+INA OUTA

V

> 3.1V

> 2V

WART

LT6700-3

2

5

5.1V

CMPZ5231B

+INB OUTB

GND

BATT

6700123 TA03

–

1µF

150k 249k

2

6700123 TA04

R1 = 400k/(V

R2 = 400k/(V

AT LOW – 0.4)

AT MAX – 0.4)

BATT

HYSTERESIS ZONES APPROXIMATELY 2% OF TRIP VOLTAGE

PowerPath IS A TRADEMARK OF LINEAR TECHNOLOGY CORPORATION

RELATED PARTS

PART NUMBER

LT1017/LT1018

LTC1441/LTC1442

LTC1998

DESCRIPTION

COMMENTS

Micropower Dual Comparator

1.1V (Min) Supply Voltage, ±1.4mV (Max) Input Offset

1.182 ±1% Reference, ±10mV (Max) Input Offset

Micropower Dual Comparator with 1% Reference

Micropower Comparator for Battery Monitoring

2.5µA Typ Supply Current, Adjustable Threshold and Hysteresis

6700123fb

LT/TP 0104 1K • PRINTED IN USA

12 ^{LinearTechnology Corporation}

1630 McCarthy Blvd., Milpitas, CA 95035-7417

●

(408) 432-1900 FAX: (408) 434-0507 www.linear.com

LINEAR TECHNOLOGY CORPORATION 2003


型号：	LT6700HS6-2#PBF
厂家：	Linear
描述：	LT6700 - Micropower, Low Voltage, Dual Comparator with 400mV Reference; Package: SOT; Pins: 6; Temperature Range: -40°C to 125°C 比较器放大器放大器电路光电二极管
文件：	总12页 (文件大小：230K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

LT6700HS6-2#PBF [Linear]

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