LT1494IMS8#PBF_技术文档

LT1494/LT1495/LT1496

1.5µA Max, Single, Dual

and Quad Over-The-Top Precision

Rail-to-Rail Input and Output Op Amps

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FEATURES

DESCRIPTIO

The LT^®1494/LT1495/LT1496 are the lowest power

(I_S≤ 1.5µA) op amps with precision specifications. The

extremely low supply current is combined with excellent

■

Low Supply Current: 1.5µA Max

■

Rail-to-Rail Input and Output

■

Low Offset Voltage: 375µV Max

amplifier specifications: input offset voltage is 375µV

maximum with a typical drift of only 0.4µV/°C, input offset

current is 100pA maximum. A minimum open-loop gain

(A_VOL) of 100V/mV ensures that gain errors are small. The

device characteristics change little over the supply range

of2.2Vto±15V. Supplyrejectionis90dBandthecommon

moderejectionratiois90dB. Operationisspecifiedfor3V,

5V and ±15V supplies. Reverse battery protection

(–18V min) and inputs that operate above the positive

supply make the LT1494/LT1495/LT1496 easy to use in

harsh environments.

Operating Temperature Range: –40°C to 125°C

Over-The-Top^TMInputs Operate Above V⁺

Wide Supply Range: 2.2V to 36V

Single Supply Input Range: –0.3V to 36V

Low Input Bias Current: 250pA

Low Input Offset Current: 20pA

High A_VOL: 100V/mV Minimum Driving 100kΩ Load

Output Sources and Sinks 500µA Load Current

Reverse Battery Protected to 18V

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APPLICATIO S

The low bias currents and offset current of the amplifier

permit the use of megohm level source resistors without

introducing significant errors. Voltage noise at 4µV_P-Pis

remarkably low considering the low supply current.

■

Battery- or Solar-Powered Systems

■

Portable Instrumentation

■

Remote Sensor Amplifier

Micropower Filter

The LT1494 is available in the 8-Pin MSOP, PDIP and SO

packages.The LT1495 is available in plastic 8-Pin PDIP

and SO packages with the standard dual op amp pinout.

The LT1496 is available in 14-Pin SO and PDIP packages.

■

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

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

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TYPICAL APPLICATION

Micropower Integrating Current Sense

TC V_OSDistribution

RESET

30

100 AMPLIFIERS

V

= ±2.5V

S

0.1µF

25

20

15

10

5

–40°C TO 85°C

V

CC

R

I

1M

–

R

S

–

1/2 LT1495

0.1Ω

1M

1/2 LT1495

V

O

+

I

L

+

10M

LOAD

1495 TA01

V

CC

0

200k

–2.0 –1.6 –1.2 –0.8 –0.4

0

0.4 0.8 1.2 1.6 2.0

TC V (µV/°C)

OS

OUTPUT SWITCHES

WHEN I dt = 0.98 V

L

1495 TA02

R

I

C = (4.9A)(SEC) FOR V = 5V

CC

(

)

S

I

= 3µA DURING INTEGRATION; I = 5µA END OF INTEGRATION

S

1

LT1494/LT1495/LT1496

W W U W

ABSOLUTE MAXIMUM RATINGS _{(Note 1)}

Total Supply Voltage (V⁺to V^–) .............................. 36V

Differential Input Voltage ......................................... 36V

Input Current ...................................................... ±10mA

Output Short-Circuit Duration.......................Continuous

Operating Temperature Range (Note 2)

Specified Temperature Range (Note 3)

LT1494C/LT1495C/LT1496C .............. –40°C to 85°C

LT1494I/LT1495I/LT1496I ................. –40°C to 85°C

LT1494H/LT1495H/LT1496H ........... –40°C to 125°C

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

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

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

LT1494C/LT1495C/LT1496C .............. –40°C to 85°C

LT1494I/LT1495I/LT1496I ................. –40°C to 85°C

LT1494H/LT1495H/LT1496H ........... –40°C to 125°C

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PACKAGE/ORDER INFORMATION

ORDER PART

NUMBER

ORDER PART

NUMBER

TOP VIEW

NC

–IN

+IN

1

2

3

4

8

7

6

5

NC

LT1494CN8

LT1494CS8

LT1494IN8

LT1494IS8

LT1494HS8

TOP VIEW

LT1494CMS8

LT1494IMS8

+

V

NC 1

–IN 2

8 NC

7 V

6 OUT

5 NC

+

OUT

NC

+IN

V

3

4

–

V

MS8 PACKAGE

8-LEAD PLASTIC MSOP

N8 PACKAGE

8-LEAD PDIP

S8 PACKAGE

8-LEAD PLASTIC SO

S8 PART MARKING

MS8 PART MARKING

T

_JMAX= 150°C, θ_JA= 250°C/ W

T_JMAX= 150°C, θ_JA= 130°C/ W (N8)

T

_JMAX= 150°C, θ_JA= 190°C/ W (S8)

1494

1494I

1494H

LTFF

LTFG

ORDER PART

NUMBER

ORDER PART

NUMBER

TOP VIEW

1

2

3

4

5

6

7

OUT D

–IN D

+IN D

14

13

12

11

10

9

OUT A

–IN A

+IN A

LT1495CN8

LT1495CS8

LT1495IN8

LT1495IS8

LT1495HS8

+

LT1496CN

LT1496CS

LT1496IN

LT1496IS

LT1496HS

OUT A

–IN A

+IN A

1

2

3

4

V

8

7

6

5

A

B

D

C

OUT B

–IN B

+IN B

A

–

+

V

B

+IN C

–IN C

OUT C

+IN B

–IN B

–

V

N8 PACKAGE

8-LEAD PDIP

S8 PACKAGE

8

OUT B

S8 PART MARKING

8-LEAD PLASTIC SO

S PACKAGE

14-LEAD PLASTIC SO

N PACKAGE

14-LEAD PDIP

T

_JMAX= 150°C, θ_JA= 130°C/ W (N8)

T_JMAX= 150°C, θ_JA= 190°C/ W (S8)

1495

1495I

1495H

T_JMAX= 150°C, θ_JA= 130°C/ W (N)

_JMAX= 150°C, θ_JA= 160°C/ W (S)

T

Consult LTC Marketing for parts specified with wider operating temperature ranges.

2

LT1494/LT1495/LT1496

ELECTRICAL CHARACTERISTICS

T_A= 25°C, V_S= 5V, 0V; V_S= 3V, 0V; V_CM= V_O= half supply, unless otherwise noted.

SYMBOL PARAMETER

CONDITIONS

V = 5V

MIN

TYP

MAX

UNITS

V

OS

Input Offset Voltage

150

200

150

200

375

475

575

µV

S

V = 3V

S

V = 5V, MS8 Package

S

V = 3V, MS8 Package

S

I

Input Bias Current

(Note 5)

250

180

20

4

185

10

500

250

1000

360

100

pA

nA

pA

B

V

CM

= 10V (Note 6)

Input Offset Current

Input Noise Voltage

Input Noise Voltage Density

Input Noise Current Density

Large-Signal Voltage Gain

(Note 5)

OS

0.1Hz to 10Hz

f = 100Hz

µV

P-P

nV/√Hz

fA/√Hz

V/mV

e

n

i

n

A

V = 5V, V = 0.25V to 4.5V, R = 100k

100

50

VOL

S

O

L

V = 3V, V = 0.25V to 2.5V, R = 100k

S

O

L

Input Voltage Range

0

36

V

CMRR

PSRR

Common Mode Rejection Ratio

V

= 0V to 4V, V = 5V

90

74

90

106

95

99

2.1

50

dB

V

mV

V

CM

S

= 0V to 10V, V = 5V

S

Power Supply Rejection Ratio

Minimum Operating Supply Voltage

Output Voltage Swing LOW

V = 2.2V to 12V, V = V = 0.5V

S

CM

O

2.2

100

410

V

OL

V

OH

No Load

I

= 100µA

210

V – 0.035

V – 0.160

SINK

+

Output Voltage Swing HIGH

No Load

= 100µA

V – 0.07

V – 0.32

+

I

SOURCE

I

Short-Circuit Current

Supply Current per Amplifier

Reverse Supply Voltage

Slew Rate

(Note 5)

(Note 6)

0.7

1.3

1.0

mA

µA

V

V/ms

kHz

SC

1.5

S

I = 10µA per Amplifier

–18

0.4

S

SR

GBW

A = –1, V = ±5V

1.0

2.7

V

S

Gain Bandwidth Product

f = 100Hz

3

LT1494/LT1495/LT1496

ELECTRICAL CHARACTERISTICS

The ● denotes the specifications which apply over the temperature range of 0°C ≤ T_A≤ 70°C, V_S= 5V, 0V; V_S= 3V, 0V; V_CM= V_O= half

supply, unless otherwise noted. (Note 3)

SYMBOL PARAMETER

CONDITIONS

V = 5V

MIN

TYP

MAX

UNITS

V

Input Offset Voltage

●

175

225

175

225

425

525

625

µV

OS

S

V = 3V

S

V = 5V, MS8 Package

S

V = 3V, MS8 Package

S

V

TC

Input Offset Voltage Drift

Input Bias Current

(Note 4)

(Note 5)

●

0.4

250

240

20

280

150

2

µV/°C

OS

I

●

1200

500

120

36

pA

nA

pA

V/mV

B

V

= 10V (Note 6)

CM

Input Offset Current

Large-Signal Voltage Gain

(Note 5)

V = 5V, V = 0.25V to 4.5V, R = 100k

●

OS

A

●

75

40

0.2

VOL

S

O

L

V = 3V, V = 0.25V to 2.5V, R = 100k

S

O

L

Input Voltage Range

●

V

CMRR

PSRR

Common Mode Rejection Ratio

V

= 0.2V to 4V, V = 5V

●

89

64

89

106

85

99

2.3

55

225

V – 0.04

V – 0.18

dB

V

mV

V

CM

S

= 0.2V to 10V, V = 5V

S

Power Supply Rejection Ratio

Minimum Operating Supply Voltage

Output Voltage Swing LOW

V = 2.4V to 12V, V = V = 0.5V

●

S

CM

O

2.4

110

450

V

No Load

●

OL

OH

I

= 100µA

SINK

+

Output Voltage Swing HIGH

No Load

= 100µA

●

V – 0.08

V – 0.36

+

I

SOURCE

I

Short-Circuit Current

Supply Current per Amplifier

(Note 5)

(Note 6)

●

0.6

1.1

1.2

mA

µA

SC

1.8

S

The ● denotes the specifications which apply over the temperature range of –40°C ≤ T_A≤ 85°C, V_S= 5V, 0V; V_S= 3V, 0V; V_CM= V_O=

half supply, unless otherwise noted. (Note 3)

SYMBOL PARAMETER

CONDITIONS

V = 5V

MIN

TYP

MAX

UNITS

V

Input Offset Voltage

●

200

250

200

250

475

575

675

µV

OS

S

V = 3V

S

V = 5V, MS8 Package

S

V = 3V, MS8 Package

S

V

TC

Input Offset Voltage Drift

Input Bias Current

(Note 4)

(Note 5)

●

0.4

250

275

20

215

115

2

µV/°C

OS

I

●

1700

pA

nA

pA

V/mV

B

V

= 10V (Note 6)

CM

Input Offset Current

Large-Signal Voltage Gain

(Note 5)

V = 5V, V = 0.25V to 4.5V, R = 100k

●

170

OS

A

●

55

30

VOL

S

O

L

V = 3V, V = 0.25V to 2.5V, R = 100k

S

O

L

Input Voltage Range

Common Mode Rejection Ratio

●

0.2

88

36

V

dB

CMRR

PSRR

V

= 0.2V to 4V, V = 5V

●

106

75

CM

S

= 0.2V to 10V, V = 5V

S

Power Supply Rejection Ratio

Minimum Operating Supply Voltage

Output Voltage Swing LOW

V = 2.7V to 12V, V = V = 0.5V

●

88

99

2.6

60

245

V – 0.05

V – 0.19

dB

V

mV

S

CM

O

2.7

120

490

V

No Load

●

OL

OH

I

= 100µA

SINK

+

Output Voltage Swing HIGH

No Load

= 100µA

●

V – 0.10

V – 0.38

+

I

SOURCE

I

Short-Circuit Current

Supply Current per Amplifier

(Note 5)

(Note 6)

●

0.4

0.9

1.5

mA

µA

SC

2.3

S

4

LT1494/LT1495/LT1496

ELECTRICAL CHARACTERISTICS

The ● denotes the specifications which apply over the temperature range of –40°C ≤ T_A≤ 125°C. V_S= 5V, 0V; V_S= 3V, 0V; V_CM= V_O=

half supply, unless otherwise noted. (Note 3)

LT1494H/LT1495H/LT1496H

SYMBOL PARAMETER

CONDITIONS

V = 5V

V = 3V

S

MIN

TYP

MAX

UNITS

V

OS

Input Offset Voltage

●

225

275

875

975

µV

S

V

TC

Input Offset Voltage Drift

Input Bias Current

(Note 4)

(Note 5)

●

0.4

3.8

0.300

0.3

25

17

3

10

2

µV/°C

OS

I

●

nA

µA

nA

V/mV

B

V

CM

= 10V (Note 6)

Input Offset Current

Large-Signal Voltage Gain

(Note 5)

V = 5V, V = 0.25V to 4.5V, R = 100k

●

2

OS

A

VOL

●

4

2

S

O

L

V = 3V, V = 0.25V to 2.5V, R = 100k

S

O

L

Input Voltage Range

Common Mode Rejection Ratio

●

0.5

72

36

V

dB

CMRR

PSRR

V

CM

V

CM

= 0.5V to 4V, V = 5V

●

95

85

S

= 0.5V to 10V, V = 5V

S

Power Supply Rejection Ratio

Minimum Operating Supply Voltage

Output Voltage Swing LOW

V = 2.7V to 12V, V = V = 0.5V

●

86

105

dB

V

mV

µA

S

CM

O

2.7

160

550

V

OL

V

OH

No Load

●

70

I

= 100µA

275

SINK

+

Output Voltage Swing HIGH

Supply Current per Amplifier

No Load

= 100µA

●

V – 140

V – 450

V – 45

+

I

V – 225

SOURCE

I

(Note 6)

●

2

5

S

T_A= 25°C, V_S= ±15V, V_CM= V_O= 0V, unless otherwise noted.

SYMBOL PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

V

Input Offset Voltage

200

575

675

µV

OS

MS8 Package

I

Input Bias Current

Input Offset Current

25

20

1000

100

pA

B

OS

A

Large-Signal Voltage Gain

Input Voltage Range

Common Mode Rejection Ratio

Power Supply Rejection Ratio

Output Voltage Swing LOW

V = ±10V, R = 100k

100

–15

100

96

360

V/mV

V

dB

V

VOL

O

L

21

CMRR

PSRR

V

= –15V to 14V

120

–14.85

–14.75

CM

V = ±5V to ±15V

S

R = 1M

–14.70

–14.50

OL

L

R = 100k

L

V

Output Voltage Swing HIGH

R = 1M

R = 100k

L

14.78

14.62

14.89

14.81

V

OH

L

I

Short-Circuit Current

Supply Current per Amplifier

0.7

1.5

1.4

mA

µA

SC

2.0

S

5

LT1494/LT1495/LT1496

ELECTRICAL CHARACTERISTICS

The ● denotes the specifications which apply over the temperature range of 0°C ≤ T_A≤ 70°C, V_S= ±15V, V_CM= V_O= 0V, unless

otherwise noted. (Note 3)

SYMBOL PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

V

Input Offset Voltage

●

225

625

725

µV

OS

MS8 Package

I

A

Input Bias Current

Input Offset Current

●

250

20

240

1200

120

pA

V/mV

V

dB

B

OS

Large-Signal Voltage Gain

Input Voltage Range

Common Mode Rejection Ratio

Power Supply Rejection Ratio

Output Voltage Swing LOW

V = ±10V, R = 100k

60

–14.8

98

VOL

O

L

21

CMRR

PSRR

V

= –14.8V to 14V

120

–14.84

–14.73

CM

V = ±5V to ±15V

94

S

R = 1M

●

–14.67

–14.46

V

OL

L

R = 100k

L

V

Output Voltage Swing HIGH

R = 1M

R = 100k

L

●

14.76

14.58

14.88

14.79

V

OH

L

I

Short-Circuit Current

Supply Current per Amplifier

●

0.6

1.3

1.6

mA

µA

SC

2.4

S

The ● denotes the specifications which apply over the temperature range of –40°C ≤ T_A≤ 85°C, V_S= ±15V, V_CM= V_O= 0V, unless

otherwise noted. (Note 3)

SYMBOL PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

V

Input Offset Voltage

●

250

675

775

µV

OS

MS8 Package

I

A

Input Bias Current

Input Offset Current

●

250

20

200

1700

170

pA

V/mV

V

dB

B

OS

Large-Signal Voltage Gain

Input Voltage Range

Common Mode Rejection Ratio

Power Supply Rejection Ratio

Output Voltage Swing LOW

V = ±10V, R = 100k

50

–14.8

96

VOL

O

L

21

CMRR

PSRR

V

= –14.8V to 14V

114

120

–14.83

–14.72

CM

V = ±5V to ±15V

92

S

R = 1M

●

–14.66

–14.44

V

OL

L

R = 100k

L

V

Output Voltage Swing HIGH

R = 1M

R = 100k

L

●

14.74

14.54

14.87

14.77

V

OH

L

I

Short-Circuit Current

Supply Current per Amplifier

●

0.4

1.1

2.0

mA

µA

SC

3.0

S

6

LT1494/LT1495/LT1496

ELECTRICAL CHARACTERISTICS

The ● denotes the specifications which apply over the temperature range of –40°C ≤ T_A≤ 125°C. V_S= ±15V, V_CM= V_O= half supply,

unless otherwise noted. (Note 3)

LT1494H/LT1495H/LT1496H

SYMBOL PARAMETER

CONDITIONS

MIN

TYP

275

3.8

0.3

70

MAX

1100

10

UNITS

µV

V

Input Offset Voltage

●

OS

I

Input Bias Current

Input Offset Current

nA

V/mV

V

dB

V

B

2

OS

A

Large-Signal Voltage Gain

Input Voltage Range

V = ±10V, R = 100k

O

21

–14.5

69

VOL

L

21

CMRR

PSRR

Common Mode Rejection Ratio

Power Supply Rejection Ratio

Output Voltage Swing LOW

V

= –14.5V to 14V

90

115

CM

V = ±5V to ±15V

89

S

V

R = 1M

●

–14.80

–14.69

–14.4

–14.2

OL

L

R = 100k

L

V

Output Voltage Swing HIGH

Supply Current per Amplifier

R = 1M

R = 100k

L

●

14.5

14.3

14.85

14.73

3

V

µA

OH

L

I

●

6

S

–40°C to 85°C but are not tested or QA sampled at these temperatures.

The LT1494I/LT1495I/LT1496I are guaranteed to meet specified

performance from –40°C to 85°C. The LT1494H/LT1495H/LT1496H are

guaranteed to meet specified performance from –40°C to 125°C.

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

of the device may be impaired.

Note 2: The LT1494C/LT1495C/LT1496C and LT1494I/LT1495I/LT1496I

are guaranteed functional over the operating temperature range of –40°C

to 85°C. The LT1494H/LT1495H/LT1496H are guaranteed functional over

the operating temperature range of –40°C to 125°C.

Note 4: This parameter is not 100% tested.

Note 5: V = 5V limits are guaranteed by correlation to V = 3V and

S

Note 3: The LT1494C/LT1495C/LT1496C are guaranteed to meet specified

performance from 0°C to 70°C. The LT1494C/LT1495C/LT1496C are

designed, characterized and expected to meet specified performance from

V = ±15V tests.

S

Note 6: V = 3V limits are guaranteed by correlation to V = 5V and

S

V = ±15V tests.

S

W

U

TYPICAL PERFORMANCE CHARACTERISTICS

Distribution of Input Offset Voltage

Supply Current vs Temperature

Minimum Supply Voltage

20

18

16

14

12

10

8

2.5

2.0

1.5

1.0

0.5

0

200

V

S

= 5V, 0V

LT1494/LT1495/

LT1496

150

100

5700 OP AMPS

T

A

= 25°C

T

A

= –40°C

T

A

= 85°C

V

S

= ±15V

50

0

V

S

= ±2.5V

6

4

2

0

–50

–400

0

200 300

400

–40 –20

0

20

40

60

80 100

1

2

3

4

5

–300 –200 –100

100

INPUT OFFSET VOLTAGE (µV)

TEMPERATURE (°C)

TOTAL SUPPLY VOLTAGE (V)

1495 G01

1495 G02

1495 G03

7

LT1494/LT1495/LT1496

W

U

TYPICAL PERFORMANCE CHARACTERISTICS

Output Saturation Voltage

vs Load Current (Output Low)

Input Bias Current

vs Common Mode Voltage

Output Saturation Voltage

vs Load Current (Output High)

1000

100

10

1000

100

10

300

200

100

1.5

V

= 5V, 0V

V

= 5V, 0V

V = 5V, 0V

S

T

= 85°C

= 25°C

A

T

= –40°C

A

T

= 85°C

A

T

= 25°C

A

T

= 85°C

A

T

= –40°C

T

= 25°C

A

T

= –40°C

A

T

= 25°C

A

0.5

T

= –40°C

T = 85°C

A

–0.5

0.1

1

10

100

1000

0.1

1

10

100

1000

2

3

6

7

–1

0

1

4

5

8

9

10

LOAD CURRENT (µA)

COMMON MODE VOLTAGE (V)

1495 G04

1495 G05

1495 G06

Gain and Phase Shift

vs Frequency

Noise Voltage Spectrum

Noise Current Spectrum

50

40

120

300

250

200

150

100

50

100

80

V

= ±2.5V

V = ±2.5V

S

V

= ±2.5V

S

100

80

30

PHASE

20

60

40

20

0

10

40

GAIN

0

20

–10

–20

–30

0

–20

–40

0

0.1

1

10

1

10

100

1

10

100

FREQUENCY (kHz)

FREQUENCY (Hz)

1495 G09

1495 G08

1495 G10

Gain Bandwidth and Phase

Margin vs Supply Voltage

0.1Hz to 10Hz

Output Voltage Noise

Capacitive Load Handling

80

70

60

50

40

30

20

10

0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0

70

60

50

40

30

20

10

0

V

= ±2.5V

V

= ±15V

CM

S

PHASE MARGIN

GBW

= 0V

A

= 1

V

A

= 5

V

A

= 10

V

20

SUPPLY VOLTAGE (V)

30

0

5

10

15

25

10

100

1000

10000

100000

TIME (1s/DIV)

CAPACITIVE LOAD (pF)

1495 G12

1495 G11

1495 G07

8

LT1494/LT1495/LT1496

W

U

TYPICAL PERFORMANCE CHARACTERISTICS

Common Mode Rejection Ratio

vs Frequency

Power Supply Rejection Ratio

vs Frequency

Output Impedance vs Frequency

100

90

100

90

1000

V

= ±2.5V

V = ±2.5V

S

POSITIVE

SUPPLY

80

100

70

60

50

60

50

A

= 10

V

10

1

NEGATIVE

SUPPLY

40

30

20

10

0

40

30

20

10

0

A

= 1

V

0.1

0.01

0.1

1

10

0.01

0.1

1

10

0.1

1

10

FREQUENCY (kHz)

1495 G13

1495 G14

1495 G15

Open-Loop Gain

V_S= 5V, 0V

Open-Loop Gain

Warm-Up Drift vs Time

V_S= ±15V

40

30

20

15

10

5

80

60

V

S

= 5V, 0V

V

= ±15V

S

20

40

20

R

= 100k

V

= ±15V

= ±2.5V

L

S

10

R

= 1M

L

R

= 1M

L

0

–20

–40

–60

R

= 100k

L

V

S

–10

–20

–30

– 40

–5

–10

–15

–20

–80

1

2

4

0

5

6

–20 –15 –10 –5

0

5

10 15 20

0

20 40 60 80 100 120 140 160 180 200

TIME AFTER POWER-UP (SEC)

1495 G16

3

OUTPUT VOLTAGE (V)

1495 G17

1495 G18

Small-Signal Response

V_S= 5V, 0V

Large-Signal Response

V_S= 5V, 0V

Small-Signal Response

V_S= ±15V

1495 G20

1495 G19

1495 G21

V_S= 5V, 0V

R_L= 1M

C_L= 100pF

V_S= ±15V

R

_L= 1M

R

_L= 1M

C_L= 100pF

9

LT1494/LT1495/LT1496

U

W U U

APPLICATIONS INFORMATION

Start-Up Characteristics

Reverse Battery

TheLT1494/LT1495/LT1496areprotectedagainstreverse

battery voltages up to 18V. In the event a reverse battery

condition occurs, the supply current is typically less than

100nA (inputs grounded and outputs open). For typical

single supply applications with ground referred loads and

feedback networks, no other precautions are required. If

the reverse battery condition results in a negative voltage

at either the input pins or output pin, the current into the

pin should be limited by an external resistor to less than

10mA.

Micropower op amps are sometimes not micropower

during start-up, wreaking havoc on low current supplies.

Intheworstcase,theremaynotbeenoughsupplycurrent

availabletotakethesystemuptonominalvoltages.Figure

1 is a graph of LT1495 supply current vs supply voltage

for the three limit cases of input offset that could occur

during start-up. The circuits are shown in Figure 2. One

circuitcreatesapositiveoffset,forcingtheoutputtocome

up saturated high. Another circuit creates a negative

offset, forcing the output to come up saturated low, while

thelastbringsuptheoutputathalfsupply.Inallcases,the

supply current is well behaved. Supply current is highest

with the output forced high, so if one amplifier is unused,

it is best to force the output low or at half supply.

Inputs

While the LT1494/LT1495/LT1496 will function normally

with its inputs taken above the positive supply, the com-

mon mode range does not extend beyond approximately

300mV below the negative supply at room temperature.

Thedevicewillnotbedamagediftheinputsaretakenlower

than 300mV below the negative supply as long as the cur-

rent out of the pin is limited to less than 10mA. However,

theoutputphaseisnotguaranteedandthesupplycurrent

will increase.

5

4

OUTPUT HIGH

3

2

OUTPUT LOW

Output

1

OUTPUT V /2

S

Thegraph,CapacitiveLoadHandling,showsamplifiersta-

bility with the output biased at half supply. If the output is

to be operated within about 100mV of the positive rail, the

allowable load capacitance is less. With this output volt-

age, theworstcaseoccursatA_V=1andlightloads, where

the load capacitance should be less than 500pF with a 5V

supply and less than 100pF with a 30V supply.

0

1

2

3

4

5

SUPPLY VOLTAGE (V)

1495 F01

Figure 1. Start-Up Characteristics

V

S

Rail-to-Rail Operation

V /2

+

–

+

–

+

S

The simplified schematic, Figure 3, details the circuit

design approach of the LT1494/LT1495/LT1496. The

amplifier topology is a three-stage design consisting of a

rail-to-rail input stage, that continues to operate with the

inputs above the positive rail, a folded cascode second

stage that develops most of the voltage gain, and a rail-to-

rail common emitter stage that provides the current gain.

–

1495 F02

OUTPUT HIGH

OUTPUT LOW

OUTPUT AT V /2

S

Figure 2. Circuits for Start-Up Characteristics

10

LT1494/LT1495/LT1496

U

W U U

APPLICATIONS INFORMATION

+

V

D1

D2

D3

D7

Q10

Q13

Q14

Q15

Q20

+

I

1

Q21

C1

+

–

IN

OUT

+

Q1 Q2

Q3

Q4

Q7

(V ) – 0.8V

Q16

Q17

Q19

D4

D5

D6

Q11

Q5

0.5

Q6

0.5

Q12

0.5

Q18

Q22

+

R1

R2

I

2

Q9

Q8

1495 F03

Figure 3. Simplified Schematic

TheinputstageisformedbytwodiffampsQ1-Q2andQ3-

Q6.ForsignalswithacommonmodevoltagebetweenV_EE

and (V_CC– 0.8V), Q1 and Q2 are active. When the input

common mode exceeds (V_CC– 0.8V), Q7 turns on,

diverting the current from diff amp Q1-Q2 to current

mirrorQ8-Q9.ThecurrentfromQ8biasesontheotherdiff

ampconsistingofPNP’sQ5-Q6andNPN’sQ3-Q4.Though

Q5-Q6 are driven from the emitters rather than the base,

the basic diff amp action is the same. When the common

modevoltageisbetween(V_CC–0.8V)andV_CC,devicesQ3

and Q4 act as followers, forming a buffer between the

amplifier inputs and the emitters of the Q5-Q6. If the

common mode voltage is taken above V_CC, Schottky

diodesD1andD2reversebiasanddevicesQ3andQ4then

act as diodes. The diff amp formed by Q5-Q6 operates

normally, however, the input bias current increases to the

emitter current of Q5-Q6, which is typically 180nA. The

graph, Input Bias Current vs Common Mode Voltage

found in the Typical Performance Characteristics section,

shows these transitions at three temperatures.

Thecollectorcurrentsofthetwo-inputpairsarecombined

in the second stage consisting of Q11 to Q16, which

furnishes most of the voltage gain. Capacitor C1 sets the

amplifier bandwidth. The output stage is configured for

maximum swing by the use of common emitter output

devices Q21 and Q22. Diodes D4 to D6 and current source

Q15 set the output quiescent current.

11

LT1494/LT1495/LT1496

U

TYPICAL APPLICATIONS N

13µA, 0kHz to 10kHz Voltage to Frequency Converter

270k

10M*

3.9M*

20M

5V

–

+

390Ω

1/2

LT1495

3.9M

+

100k

562k*

5V

1µF

V

IN

–

0V TO 2.5V

LTC^®1440

0.0082µF

+

1.2

REFERENCE

LTC1440

12pF

1N5712

1N4148

3.6M TYP

SELECT FOR 100Hz

360k

Q1: ZTX-849

AT V = 0.025V

IN

*1% METAL FILM

†

POLYSTYRENE

39k

10M

0V – 2.5V = 0kHz – 10kHz

†

0.05µF

100pF

OUTPUT

0kHz TO 10kHz

SUPPLY CURRENT = 6.2µA QUIESCENT

= 13.3µA AT f = 10kHz

15k

–

Q1

LINEARITY: ±0.03%

1/2

LT1495

PSRR (4.4V TO 36V): 10ppm/V

TEMPERATURE DRIFT: 250ppm/°C

+

1495 TA07

6µA, A_V= 1000, Chopper Stabilized Amplifier

0.2µF

1µF

5V

φ1

φ2

1µF

+

φ2

1M

1/2

LT1495

INPUT

–

1M

1/2

LT1495

OUTPUT

–

10M

+

–5V

φ1

10k

10M

10k

10M

φ1

–

5V

GAIN: 1000

–

1/2

LTC1441

OFFSET: 1µV

0.047µF

DRIFT: 50nV/°C

+

1/2

LTC1441

φ2

SUPPLY CURRENT: 5.5µA

BANDWIDTH: 0.2Hz

CLOCK RATE: 4Hz

10M

+

–5V

1495 TA08

CD4016 QUAD

12

LT1494/LT1495/LT1496

U

TYPICAL APPLICATIONS N

Filter Frequency Response

6th Order 10Hz Elliptic Lowpass Filter

0

10k

100k

15nF

215k

15nF

100nF

–10

e

+

in

215k

30nF

–20

–30

–40

–50

–60

1/2 LT1495

215k

100nF

100k

–

200k

10nF

V

S

= 5V, 0V

I

= 2µA + e /150k

S

in

ZEROS AT 50Hz AND 60Hz

10k

1

10

100

1000

80.6k

FREQUENCY (Hz)

15nF

169k

15nF

100nF

LT1495/96 • TA04

+

169k

30nF

OUTPUT

1/2 LT1495

169k

100nF

100k

–

200k

10nF

1495 TA03

U

PACKAGE DESCRIPTION

MS8 Package

8-Lead Plastic MSOP

(Reference LTC DWG # 05-08-1660)

0.118 ± 0.004*

(3.00 ± 0.102)

8

7

6

5

0.118 ± 0.004**

(3.00 ± 0.102)

0.193 ± 0.006

(4.90 ± 0.15)

1

2

3

4

0.043

(1.10)

MAX

0.034

(0.86)

REF

0.007

(0.18)

0° – 6° TYP

SEATING

PLANE

0.009 – 0.015

(0.22 – 0.38)

0.021 ± 0.006

(0.53 ± 0.015)

0.005 ± 0.002

(0.13 ± 0.05)

0.0256

(0.65)

BSC

MSOP (MS8) 1100

* DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH,

PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE

** DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.

INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE

13

LT1494/LT1495/LT1496

U

PACKAGE DESCRIPTION

N8 Package

8-Lead PDIP (Narrow .300 Inch)

(Reference LTC DWG # 05-08-1510)

0.400*

(10.160)

MAX

8

7

6

5

4

0.255 ± 0.015*

(6.477 ± 0.381)

1

2

3

0.130 ± 0.005

0.300 – 0.325

0.045 – 0.065

(3.302 ± 0.127)

(1.143 – 1.651)

(7.620 – 8.255)

0.065

(1.651)

TYP

0.009 – 0.015

(0.229 – 0.381)

0.125

0.020

(0.508)

MIN

(3.175)

MIN

+0.035

0.325

–0.015

0.018 ± 0.003

(0.457 ± 0.076)

0.100

(2.54)

BSC

+0.889

8.255

(

)

–0.381

N8 1098

*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.

MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm)

S8 Package

8-Lead Plastic Small Outline (Narrow .150 Inch)

(Reference LTC DWG # 05-08-1610)

0.189 – 0.197*

(4.801 – 5.004)

7

5

8

6

0.150 – 0.157**

(3.810 – 3.988)

0.228 – 0.244

(5.791 – 6.197)

SO8 1298

1

3

4

2

0.010 – 0.020

(0.254 – 0.508)

× 45°

0.053 – 0.069

(1.346 – 1.752)

0.004 – 0.010

(0.101 – 0.254)

0.008 – 0.010

(0.203 – 0.254)

0°– 8° TYP

0.016 – 0.050

(0.406 – 1.270)

0.050

(1.270)

BSC

0.014 – 0.019

(0.355 – 0.483)

TYP

*DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH

SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE

**DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD

FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE

14

LT1494/LT1495/LT1496

U

PACKAGE DESCRIPTION

N Package

14-Lead PDIP (Narrow .300 Inch)

(Reference LTC DWG # 05-08-1510)

0.770*

(19.558)

MAX

14

13

12

11

10

9

8

7

0.255 ± 0.015*

(6.477 ± 0.381)

1

2

3

5

6

4

0.300 – 0.325

(7.620 – 8.255)

0.045 – 0.065

(1.143 – 1.651)

0.130 ± 0.005

(3.302 ± 0.127)

0.020

(0.508)

MIN

0.065

(1.651)

TYP

0.009 – 0.015

(0.229 – 0.381)

+0.035

0.325

0.005

(0.125)

MIN

–0.015

0.125

(3.175)

MIN

0.018 ± 0.003

+0.889

8.255

(0.457 ± 0.076)

0.100

(

)

–0.381

(2.54)

BSC

*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.

MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm)

N14 1098

S Package

14-Lead Plastic Small Outline (Narrow .150 Inch)

(Reference LTC DWG # 05-08-1610)

0.337 – 0.344*

(8.560 – 8.738)

14

13

12

11

10

9

8

0.228 – 0.244

0.150 – 0.157**

(5.791 – 6.197)

(3.810 – 3.988)

1

2

3

4

5

6

7

0.010 – 0.020

(0.254 – 0.508)

× 45°

0.053 – 0.069

(1.346 – 1.752)

0.004 – 0.010

(0.101 – 0.254)

0.008 – 0.010

(0.203 – 0.254)

0° – 8° TYP

0.050

(1.270)

BSC

0.014 – 0.019

(0.355 – 0.483)

TYP

0.016 – 0.050

(0.406 – 1.270)

S14 1298

*DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH

SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE

**DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD

FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE

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.

15

LT1494/LT1495/LT1496

U

TYPICAL APPLICATIONS N

0nA to 200nA Current Meter

Battery Current Monitor

100pF

I

L

R

SENSE

0.1Ω

CHARGE

R1

12V

DISCHARGE

R

10M

5V

R

R4

A

–

10k

–

1/2

LT1495

1.5V

–

A2

A1

1/2 LT1495

1/2

LT1495

R

INPUT

CURRENT

A

+

R2

9k

+

1.5V

R3

2N3904

DISCHARGE

2N3904

CHARGE

I

= 3µA WHEN I = 0

IN

S

2k

R

NO ON/OFF SWITCH

REQUIRED

B

A

FULL-SCALE

ADJUST

V

= I

R

SENSE

O

L

(

)

OUT

FOR R = 1k, R = 10k

R

A

B

0µA TO

200µA

µA

V

O

L

= 1V/A

1495 TA06

I

1495 TA05

High Side Current Sense

V

= 2.7V TO 36V

S

R

B

R

A

V

= I

R

S

O

L

(_R)

1k

A

–

+

FOR R = 1k, R = 10k, R = 1Ω

A

B

S

R

SENSE

1Ω

V

LT1494

O

L

= 10 V/A

I

OUTPUT OFFSET ≈ I • R ≈ 10mV

OUTPUT CLIPS AT V – 2.4V

+

S

B

R

B

I

V

O

L

LOAD

10k

_

1495 TA09

RELATED PARTS

PART NUMBER

LTC^®1440/41/42

LTC1443/44/45

DESCRIPTION

COMMENTS

Micropower Single/Dual Comparators with 1% Reference

Micropower Quad Comparators with 1% Reference

LTC1440: Single, LTC1441/42: Dual

LTC1443: 1.182 Reference

LTC1444/45: 1.221V Reference and Adjustable Hysteresis

LT1466/LT1467

LT1490A/LT1491A

LTC1540

75µA Dual/Quad Rail-to-Rail Input and Output Op Amps

50µA Dual/Quad Rail-to-Rail Input and Output Op Amps

Nanopower Single Comparator with 1% Reference

390µV V

950µV V

, Gain Bandwidth = 120kHz

, Gain Bandwidth = 200kHz

OS(MAX)

350nA Supply Current

225µV V , I = 55µA (MAX), Gain-Bandwidth = 200kHz

LT1636

Single Over-The-Top Micropower,

OS(MAX)

S

Rail-to-Rail Input and Output Op Amp

Shutdown Pin, MSOP

LT1672/LT1673/LT1674

2µA MAX, A ≥ 5 Single/Dual/Quad Over-The-Top Precision

Decompensated Version of the LT1494/LT1495/LT1496

A ≥ 5, Gain-Bandwidth = 12kHz

V

Rail-to-Rail Input and Output Op Amps

55µA Dual/Quad Single Supply Op Amps

17µA Dual/Quad Single Supply Op Amps

LT2078/LT2079

LT2178/LT2179

LT1782

120µV V

, Gain Bandwidth = 200kHz

, Gain Bandwidth = 60kHz

OS(MAX)

Micropower, Over-The-Top, SOT-23, Rail-to-Rail

Input and Output Op Amp

SOT-23, 800µV V

, I = 55µA (Max),

OS(MAX) S

Gain-Bandwidth = 200kHz, Shutdown Pin

LT1783

1.2MHz, Over-The-Top, Micropower, Rail-to-Rail

Input and Output Op Amp in SOT-23

SOT-23, 800µV V , I = 300µA (Max),

Gain-Bandwidth = 1.2MHz, Shutdown Pin

OS(MAX)

S

149456fb LT/TP 0801 1.5K REV B • PRINTED IN USA

Linear Technology Corporation

●

1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408)432-1900

16

●

FAX: (408) 434-0507 TELEX: 499-3977 www.linear.com

LINEAR TECHNOLOGY CORPORATION 1997


型号：	LT1494IMS8#PBF
厂家：	Linear
描述：	LT1494 - 1.5uA Max, Single, Dual and Quad Precision Rail-to-Rail Input and Output Op Amps; Package: MSOP; Pins: 8; Temperature Range: -40°C to 85°C 放大器光电二极管
文件：	总16页 (文件大小：255K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

LT1494IMS8#PBF [Linear]

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