LT1677IS8#PBF_技术文档

LT1677

Low Noise, Rail-to-Rail

Precision Op Amp

U

FEATURES

DESCRIPTIO

The LT^®1677 features the lowest noise performance avail-

able for a rail-to-rail operational amplifier: 3.2nV/√Hz

wideband noise, 1/f corner frequency of 13Hz and 90nV

peak-to-peak 0.1Hz to 10Hz noise. Low noise is combined

with outstanding precision: 20µV offset voltage and

0.2µV/°C drift, 130dB common mode and power supply

rejection and 7.2MHz gain bandwidth product. The com-

mon mode range exceeds the power supply by 100mV.

■

Rail-to-Rail Input and Output

100% Tested Low Voltage Noise:

■

3.2nV/√Hz Typ at 1kHz

4.5nV/√Hz Max at 1kHz

■

Offset Voltage: 60µV Max

■

Low V_OSDrift: 0.2µV/°C Typ

■

Low Input Bias Current: 20nA Max

■

Wide Supply Range: 3V to ±18V

■

High A_VOL: 7V/µV Min, R_L= 10k

The voltage gain of the LT1677 is extremely high, 19 million

(typical) driving a 10k load.

■

High CMRR: 109dB Min

■

High PSRR: 108dB Min

In the design, processing and testing of the device, particular

attention has been paid to the optimization of the entire

distribution of several key parameters. Consequently, the

specifications have been spectacularly improved compared

to competing rail-to-rail amplifiers.

■

Gain Bandwidth Product: 7.2MHz

■

Slew Rate: 2.5V/µs

■

Operating Temperature Range: –40°C to 85°C

U

APPLICATIO S

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

All other trademarks are the property of their respective owners.

■

Low Noise Signal Processing

■

Microvolt Accuracy Threshold Detection

■

Strain Gauge Amplifiers

Tape Head Preamplifiers

■

Direct Coupled Audio Gain Stages

■

Infrared Detectors

■

Battery-Powered Microphones

U

TYPICAL APPLICATIO

Distribution of Offset Voltage

25

T

= 25°C

= ±15V

A

S

3V Electret Microphone Amplifier

V

20

15

A

= –100

R3

V

1.5V

1M

C1

R1

10k

1.5V

7

R2

10k

0.68µF

TO PA

OR

PANASONIC

ELECTRET

CONDENSER

–

+

2

3

HEADPHONES

10

5

6

MICROPHONE

WM-61

www.panasonic.com/pic

(714) 373-7334

LT1677

4

23Hz

HIGHPASS

1677 TA01

–1.5V

0

–40 –30 –20 –10

10 20 30 40

INPUT OFFSET VOLTAGE (µV)

1677 TA02

1677fa

1

LT1677

W W U W

U W

PACKAGE/ORDER I FOR ATIO

TOP VIEW

U

ABSOLUTE AXI U RATI GS

(Note 1)

V

OS

TRIM

Supply Voltage ...................................................... ±22V

Input Voltages (Note 2) ............ 0.3V Beyond Either Rail

Differential Input Current (Note 2) ..................... ± 25mA

Output Short-Circuit Duration (Note 3)............ Indefinite

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

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

Operating Temperature Range

LT1677C (Note 4) ............................. –40°C to 85°C

LT1677I ............................................. –40°C to 85°C

Specified Temperature Range

OS

1

2

3

4

8

7

6

5

TRIM

–IN

–

+

+V

S

OUT

NC

+IN

–V

S

N8 PACKAGE

8-LEAD PDIP

S8 PACKAGE

8-LEAD PLASTIC SO

T_JMAX= 150°C, θ_JA= 150°C/ W (N8)

T_JMAX= 150°C, θ_JA= 190°C/ W (S0-8)

S8 PART MARKING

ORDER PART NUMBER

LT1677CS8

LT1677IS8

LT1677CN8

LT1677IN8

1677

1677I

LT1677C (Note 5) ............................. –40°C to 85°C

LT1677I ............................................. –40°C to 85°C

Order Options Tape and Reel: Add #TR

Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF

Lead Free Part Marking: http://www.linear.com/leadfree/

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

ELECTRICAL CHARACTERISTICS

The

S

●

denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at T = 25°C. V = 3V, V = V = 1.7V; V = 5V, V = V = 2.5V unless otherwise noted.

A

CM

O

S

CM

O

SYMBOL

PARAMETER

CONDITIONS (Note 6)

MIN

TYP

MAX

UNITS

V

Input Offset Voltage (Note 11)

35

55

75

90

150

210

µV

OS

0°C ≤ T ≤ 70°C

●

A

–40°C ≤ T ≤ 85°C

A

V

= V + 0.1V

150

180

200

400

550

650

µV

CM

S

= V – 0.2V, 0°C ≤ T ≤ 70°C

●

S

A

= V – 0.3V, –40°C ≤ T ≤ 85°C

S

A

V

= –0.1V

1.5

1.8

2.0

5.0

6.0

6.5

mV

CM

= 0V, 0°C ≤ T ≤ 70°C

●

A

= 0V, –40°C ≤ T ≤ 85°C

A

∆V

Average Input Offset Drift (Note 10)

Long Term Input Voltage Stability

Input Bias Current (Note 11)

SO-8

N8

●

0.40

0.20

2.0

1.5

µV/°C

OS

∆Temp

∆V

∆Time

0.3

µV/Mo

OS

I

±2

±3

±7

± 20

± 35

± 50

nA

B

0°C ≤ T ≤ 70°C

–40°C ≤ T ≤ 85°C

●

A

V

= V + 0.1V

0.19

0.25

0.40

0.60

0.75

µA

CM

S

= V – 0.2V, 0°C ≤ T ≤ 70°C

●

S

A

= V – 0.3V, –40°C ≤ T ≤ 85°C

S

A

V

= –0.1V

–1.2

–2.0

–2.3

–0.41

–0.45

–0.47

µA

CM

= 0V, 0°C ≤ T ≤ 70°C

●

A

= 0V, –40°C ≤ T ≤ 85°C

A

I

Input Offset Current (Note 11)

4

5

8

15

20

40

nA

OS

0°C ≤ T ≤ 70°C

●

A

–40°C ≤ T ≤ 85°C

A

V

= V + 0.1V

6

10

15

30

40

65

nA

CM

S

= V – 0.2V, 0°C ≤ T ≤ 70°C

●

S

A

= V – 0.3V, –40°C ≤ T ≤ 85°C

S

A

V

= –0.1V

20

25

30

100

150

160

nA

CM

= 0V, 0°C ≤ T ≤ 70°C

●

A

= 0V, –40°C ≤ T ≤ 85°C

nA

A

1677fa

2

LT1677

ELECTRICAL CHARACTERISTICS

otherwise noted.

The

●

denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at T = 25°C. V = 3V, V = V = 1.7V; V = 5V, V = V = 2.5V unless

A

S

CM

O

S

CM

O

SYMBOL PARAMETER

CONDITIONS (Note 6)

MIN

TYP

MAX

UNITS

e

Input Noise Voltage

0.1Hz to 10Hz (Note 7)

90

180

600

nV

P-P

nV

P-P

nV

P-P

n

V

= V

= 0V

CM

S

Input Noise Voltage Density (Note 8)

f = 10Hz

5.2

7

25

nV/√Hz

O

V

= V , f = 10Hz

= 0V, f = 10Hz

CM

S O

O

f = 1kHz

3.2

5.3

17

4.5

nV/√Hz

O

V

= V , f = 1kHz

= 0V, f = 1kHz

CM

S O

O

i

Input Noise Current Density

Input Voltage Range

f = 10Hz

f = 1kHz

O

1.2

0.3

pA/√Hz

n

O

V

–0.1

0

V + 0.1V

V

CM

S

0°C ≤ T ≤ 70°C

●

V – 0.2V

A

S

–40°C ≤ T ≤ 85°C

V – 0.3V

S

A

R

IN

Input Resistance

Common Mode

2

GΩ

C

Input Capacitance

4.2

pF

IN

CMRR

Common Mode Rejection Ratio (Note 11)

V = 3V

S

V

= –0.1V to 3.1V

= 0V to 2.7V

55

53

68

67

dB

CM

●

V = 5V

S

V

= –0.1V to 5.1V

= 0V to 4.7V

60

58

73

72

dB

CM

●

PSRR

Power Supply Rejection Ratio

Large-Signal Voltage Gain

V = 2.7V to 40V, V = V = 1.7V

108

105

125

120

dB

S

CM

O

V = 3.1V to 40V, V = V = 1.7V

S

CM

O

A

V = 3V, R ≥ 10k, V = 2.5V to 0.7V

0.6

0.4

4

3

V/µV

VOL

S

L

O

0°C ≤ T ≤ 70°C

●

A

–40°C ≤ T ≤ 85°C

A

V = 3V, R ≥ 2k, V = 2.2V to 0.7V

0.5

0.4

1

0.9

0.8

V/µV

S

L

O

0°C ≤ T ≤ 70°C

●

A

–40°C ≤ T ≤ 85°C

A

V = 3V, R ≥ 600Ω, V = 2.2V to 0.7V

0.20

0.15

0.10

0.43

0.40

0.35

V/µV

S

L

O

0°C ≤ T ≤ 70°C

●

A

–40°C ≤ T ≤ 85°C

A

V = 5V, R ≥ 10k, V = 4.5V to 0.7V

0.8

0.7

5

4

V/µV

S

L

O

0°C ≤ T ≤ 70°C

●

A

–40°C ≤ T ≤ 85°C

A

V = 5V, R ≥ 2k, V = 4.2V to 0.7V

0.40

0.35

0.25

0.9

0.8

0.6

V/µV

S

L

O

0°C ≤ T ≤ 70°C

●

A

–40°C ≤ T ≤ 85°C

A

V = 5V, R ≥ 600Ω, V = 4.2V to 0.7V

0.35

0.30

0.20

0.67

0.60

0.45

V/µV

S

L

O

0°C ≤ T ≤ 70°C

●

A

–40°C ≤ T ≤ 85°C

A

1677fa

3

LT1677

ELECTRICAL CHARACTERISTICS

The

●

denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at T = 25°C. V = 3V, V = V = 1.7V; V = 5V, V = V = 2.5V unless

A

S

CM

O

S

CM

O

otherwise noted.

SYMBOL PARAMETER

V

CONDITIONS (Note 6)

MIN

TYP

MAX

UNITS

Output Voltage Swing Low (Note 11)

Output Voltage Swing High (Note 11)

Output Short-Circuit Current (Note 3)

Above GND

OL

I

= 0.1mA

110

125

130

170

200

230

mV

SINK

0°C ≤ T ≤ 70°C

●

A

–40°C ≤ T ≤ 85°C

A

Above GND

I

= 2.5mA

170

195

205

250

320

350

mV

SINK

0°C ≤ T ≤ 70°C

●

A

–40°C ≤ T ≤ 85°C

A

Above GND

I

= 10mA

370

440

465

500

600

650

mV

SINK

0°C ≤ T ≤ 70°C

●

A

–40°C ≤ T ≤ 85°C

A

V

Below V

OH

S

I

= 0.1mA

75

85

93

170

200

250

mV

SOURCE

0°C ≤ T ≤ 70°C

●

A

–40°C ≤ T ≤ 85°C

A

Below V

S

I

= 2.5mA

170

195

205

300

350

375

mV

SOURCE

0°C ≤ T ≤ 70°C

●

A

–40°C ≤ T ≤ 85°C

A

Below V

S

I

= 10mA

450

510

525

700

800

850

mV

SOURCE

0°C ≤ T ≤ 70°C

●

A

–40°C ≤ T ≤ 85°C

A

I

V = 3V

15

14

13

22

20

19

mA

SC

S

0°C ≤ T ≤ 70°C

●

A

–40°C ≤ T ≤ 85°C

A

V = 5V

20

18

17

29

27

25

mA

S

0°C ≤ T ≤ 70°C

●

A

–40°C ≤ T ≤ 85°C

A

SR

Slew Rate (Note 13)

A = –1

1.7

1.5

1.2

2.5

2.3

2.0

V/µs

V

R ≥ 10k, 0°C ≤ T ≤ 70°C

●

L

A

R ≥ 10k, –40°C ≤ T ≤ 85°C

L

A

GBW

Gain Bandwidth Product (Note 11)

Settling Time

f = 100kHz

4.5

3.8

3.7

7.2

6.2

5.8

MHz

O

f = 100kHz, 0°C ≤ T ≤ 70°C

●

O

A

f = 100kHz, –40°C ≤ T ≤ 85°C

O

A

t

2V Step 0.1%, A = +1

2V Step 0.01%, A = +1

2.1

3.5

µs

S

V

R

Open-Loop Output Resistance

Closed-Loop Output Resistance

I

= 0

OUT

V

80

1

Ω

O

A = 100, f = 10kHz

I

Supply Current (Note 12)

2.60

2.75

2.80

3.4

3.7

3.8

mA

S

0°C ≤ T ≤ 70°C

●

A

–40°C ≤ T ≤ 85°C

A

1677fa

4

LT1677

ELECTRICAL CHARACTERISTICS

The

●

denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at T = 25°C. V = ±15V, V = V = 0V unless otherwise noted.

A

S

CM

O

SYMBOL

PARAMETER

CONDITIONS (Note 6)

MIN

TYP

MAX

UNITS

V

Input Offset Voltage

20

30

45

60

120

180

µV

OS

0°C ≤ T ≤ 70°C

●

A

–40°C ≤ T ≤ 85°C

A

V

= 15.1V

= 14.8V, 0°C ≤ T ≤ 70°C

= 14.7V, –40°C ≤ T ≤ 85°C

150

180

200

400

550

650

µV

CM

●

A

V

= –15.1V

= –15V, 0°C ≤ T ≤ 70°C

= –15V, –40°C ≤ T ≤ 85°C

1.5

1.8

2.0

5.0

6.0

6.5

mV

CM

●

A

∆V

∆Temp

∆V

∆Time

Average Input Offset Drift (Note 10)

Long Term Input Voltage Stability

Input Bias Current

SO-8

N8

●

0.40

0.20

2.0

1.5

µV/°C

OS

0.3

µV/Mo

OS

I

±2

±3

±7

± 20

± 35

± 50

nA

B

0°C ≤ T ≤ 70°C

–40°C ≤ T ≤ 85°C

●

A

V

= 15.1V

= 14.8V, 0°C ≤ T ≤ 70°C

= 14.7V, –40°C ≤ T ≤ 85°C

0.19

0.20

0.25

0.40

0.60

0.75

µA

CM

●

A

V

= –15.1V

= –15V, 0°C ≤ T ≤ 70°C

= –15V, –40°C ≤ T ≤ 85°C

–1.2

–2.0

–2.3

–0.42

–0.46

–0.48

µA

CM

●

A

I

Input Offset Current

3

5

8

15

20

40

nA

OS

0°C ≤ T ≤ 70°C

●

A

–40°C ≤ T ≤ 85°C

A

V

= 15.1V

= 14.8V, 0°C ≤ T ≤ 70°C

= 14.7V, –40°C ≤ T ≤ 85°C

5

8

12

25

35

60

nA

CM

●

A

V

= –15.1V

= –15V, 0°C ≤ T ≤ 70°C

= –15V, –40°C ≤ T ≤ 85°C

20

25

30

105

160

170

nA

CM

●

A

e

Input Noise Voltage

0.1Hz to 10Hz (Note 7)

90

180

600

nV

P-P

nV

P-P

nV

P-P

n

V

= 15V

= –15V

CM

Input Noise Voltage Density

f = 10Hz

5.2

7

25

nV/√Hz

O

V

= 15V, f = 10Hz

= –15V, f = 10Hz

CM

O

f = 1kHz

3.2

5.3

17

4.5

nV/√Hz

O

V

= 15V, f = 1kHz

= –15V, f = 1kHz

CM

O

V

O

i

Input Noise Current Density

Input Voltage Range

f = 10Hz

f = 1kHz

O

1.2

0.3

pA/√Hz

n

O

V

–15.1

–15.0

15.1

14.8

14.7

V

CM

0°C ≤ T ≤ 70°C

●

A

–40°C ≤ T ≤ 85°C

A

R

Input Resistance

Input Capacitance

Common Mode

2

GΩ

IN

C

4.2

pF

IN

1677fa

5

LT1677

ELECTRICAL CHARACTERISTICS

The

●

denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at T = 25°C. V = ± 15V, V = V = 0V unless otherwise noted.

A

S

CM

O

SYMBOL

PARAMETER

CONDITIONS (Note 6)

MIN

TYP

MAX

UNITS

CMRR

Common Mode Rejection Ratio

V

= –13.3V to 14V

109

105

130

124

dB

CM

●

V

= –15.1V to 15.1V

= –15V to 14.7V

74

72

95

91

dB

CM

PSRR

Power Supply Rejection Ratio

Large-Signal Voltage Gain

V = ±1.7V to ±18V

106

103

130

125

dB

S

V = 2.7V to 40V

V = 3.1V to 40V

108

105

125

120

dB

S

A

V

R ≥ 10k, V = ±14V

7

4

3

19

13

8

V/µV

VOL

L

O

0°C ≤ T ≤ 70°C

●

A

–40°C ≤ T ≤ 85°C

A

R ≥ 2k, V = ±13.5V

0.50

0.30

0.15

0.75

0.67

0.24

V/µV

L

O

0°C ≤ T ≤ 70°C

●

A

–40°C ≤ T ≤ 85°C

A

R ≥ 600Ω, V = ±10V

0.2

0.5

V/µV

L

O

Output Voltage Swing Low

Above –V

OL

S

I

= 0.1mA

A

110

125

130

170

200

230

mV

SINK

0°C ≤ T ≤ 70°C

–40°C ≤ T ≤ 85°C

●

A

Above –V

S

I

= 2.5mA

170

195

205

250

320

350

mV

SINK

0°C ≤ T ≤ 70°C

●

A

–40°C ≤ T ≤ 85°C

A

Above –V

S

I

= 10mA

370

440

450

500

600

650

mV

SINK

0°C ≤ T ≤ 70°C

●

A

–40°C ≤ T ≤ 85°C

A

V

Output Voltage Swing High

Below +V

S

OH

I

= 0.1mA

110

130

140

170

200

250

mV

SOURCE

0°C ≤ T ≤ 70°C

●

A

–40°C ≤ T ≤ 85°C

A

Below +V

S

I

= 2.5mA

A

210

240

250

300

350

375

mV

SOURCE

0°C ≤ T ≤ 70°C

–40°C ≤ T ≤ 85°C

●

A

Below +V

S

I

= 10mA

A

520

590

620

700

800

850

mV

SOURCE

0°C ≤ T ≤ 70°C

●

–40°C ≤ T ≤ 85°C

A

I

Output Short-Circuit Current (Note 3)

Slew Rate

25

20

18

35

30

28

mA

SC

0°C ≤ T ≤ 70°C

●

A

–40°C ≤ T ≤ 85°C

A

SR

R ≥ 10k (Note 9)

1.7

1.5

1.2

2.5

2.3

2.0

V/µs

L

R ≥ 10k (Note 9) 0°C ≤ T ≤ 70°C

●

L

A

R ≥ 10k (Note 9) –40°C ≤ T ≤ 85°C

L

A

GBW

Gain Bandwidth Product

f = 100kHz

4.5

3.8

3.7

7.2

6.2

5.8

MHz

O

f = 100kHz, 0°C ≤ T ≤ 70°C

●

O

A

f = 100kHz, –40°C ≤ T ≤ 85°C

O

A

1677fa

6

LT1677

ELECTRICAL CHARACTERISTICS

The

●

denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at T = 25°C. V = ± 15V, V = V = 0V unless otherwise noted.

A

S

CM

O

SYMBOL

PARAMETER

CONDITIONS (Note 6)

MIN

TYP

MAX

UNITS

THD

Total Harmonic Distortion

Settling Time

R = 2k, A = 1, f = 1kHz, V = 10V

P-P

0.0006

%

L

V

O

t

10V Step 0.1%, A = +1

5

6

µs

S

V

10V Step 0.01%, A = +1

V

R

O

Open-Loop Output Resistance

Closed-Loop Output Resistance

I

= 0

OUT

V

80

1

Ω

A = 100, f = 10kHz

I

Supply Current

2.75

3.00

3.10

3.5

3.9

4.0

mA

S

0°C ≤ T ≤ 70°C

●

A

–40°C ≤ T ≤ 85°C

A

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 inputs are protected by back-to-back diodes. Current limiting

resistors are not used in order to achieve low noise. If differential input

voltage exceeds ±1.4V, the input current should be limited to 25mA. If the

common mode range exceeds either rail, the input current should be

limited to 10mA.

Note 3: A heat sink may be required to keep the junction temperature

below absolute maximum.

Note 4: The LT1677C and LT1677I are guaranteed functional over the

Operating Temperature Range of –40°C to 85°C.

Note 6: Typical parameters are defined as the 60% yield of parameter

distributions of individual amplifier; i.e., out of 100 LT1677s, typically 60

op amps will be better than the indicated specification.

Note 7: See the test circuit and frequency response curve for 0.1Hz to

10Hz tester in the Applications Information section of the LT1677 data

sheet.

Note 8: Noise is 100% tested at ±15V supplies.

Note 9: Slew rate is measured in A = –1; input signal is ±7.5V, output

V

measured at ±2.5V.

Note 10: This parameter is not 100% tested. V = 3V and 5V limits are

S

guaranteed by correlation to V = ±15V test.

S

Note 11: V = 5V limits are guaranteed by correlation to V = 3V and

S

V = ±15V tests.

S

Note 5: The LT1677C is guaranteed to meet specified performance from

0°C to 70°C. The LT1677C 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 LT1677I is guaranteed to meet

specified performance from –40°C to 85°C.

Note 12: V = 3V limits are guaranteed by correlation to V = 5V and

S

V = ±15V tests.

S

Note 13: Guaranteed by correlation to slew rate at V = ±15V and GBW at

S

V = 3V and V = ±15V tests.

S

U W

TYPICAL PERFOR A CE CHARACTERISTICS

Voltage Noise vs Frequency

0.1Hz to 10Hz Voltage Noise

0.01Hz to 1Hz Voltage Noise

100

10

1

1/f CORNER 10Hz

< –14.5V

V

CM

1/f CORNER 8.5Hz

V

> 14.5V

V

CM

–13.5V TO 14.5V

1/f CORNER 13Hz

V

S

A

= ±15V

= 25°C

T

0

20

40

60

80

100

0

2

4

6

8

10

0.1

1

10

FREQUENCY (Hz)

100

1000

TIME (SECONDS)

1677 G01

1677 G03

1677 G04

1677fa

7

LT1677

TYPICAL PERFOR A CE CHARACTERISTICS

U W

Input Bias Current

vs Temperature

Voltage Noise vs Temperature

Current Noise vs Frequency

10

7

6

5

4

3

2

10

9

8

7

6

5

4

3

2

1

0

V

T

= ±15V

= 25°C

V

= ±15V

S

V

= ±15V

CM

S

A

S

V

= 0V

CM

= 0V

10Hz

1kHz

V

< –13.5V

CM

1/f CORNER 180Hz

1

V

CM

–13.5V TO 14.5V

1/f CORNER 90Hz

1/f CORNER 60Hz

100

V

> 14.5V

CM

0.1

10

1000

10000

–50

0

25

50

75 100 125

–50

0

25

50

75 100 125

–25

FREQUENCY (Hz)

TEMPERATURE (°C)

1677 G07

1677 G08

1677 G05

Offset Voltage Shift

vs Common Mode

Input Bias Current

vs Temperature

Input Bias Current Over the

Common Mode Range

600

500

400

300

200

100

2.5

2.0

250

800

600

V

= ±15V

V

= ±15V

= 25°C

S

A

200

150

100

50

T

V

= –14V

CM

1.5

V

IS REFERRED

CM

OS

CURRENT OUT OF DUT

400

TO V = 0V

1.0

V

= –13.6V

V

= 15.15V

CM

200

0.5

INPUT BIAS CURRENT

= 14.3V

0

V

CM

–0.5

–1.0

–1.5

–2.0

–2.5

–50

–100

–150

–200

–250

–200

–400

–600

–800

V

= –15.3V

CM

V

= 14.7V

CURRENT INTO DUT

CM

V

T

= ±1.5V TO ±15V

= 25°C

S

A

5 TYPICAL PARTS

+

–

–1.0

V

1.0 2.0 –0.8 –0.4

–

V

0.4

–50

0

25

50

75 100 125

–16 –12 –8 –4

0

4

8

12 16

–25

+

TEMPERATURE (°C)

COMMON MODE INPUT VOLTAGE (V)

V

– V (V)

V

– V (V)

CM

1677 G10

1677 G06

1677 G09

Distribution of Input Offset

Voltage Drift (N8)

Distribution of Input Offset

Voltage Drift (SO-8)

Warm-Up Drift

30

25

20

15

10

5

10

8

50

45

40

35

30

25

20

15

10

5

V

T

= ±15V

V

T

= ±15V

V

T

= ±15V

= 25°C

S

A

S

A

S

A

= –40°C TO 85°C

201 PARTS (5 LOTS)

167 PARTS (4 LOTS)

SO PACKAGE

6

N PACKAGE

4

2

0

–0.8

0

0.4 0.8 1.2 1.6 2.0

–0.4

0.6

INPUT OFFSET VOLTAGE DRIFT (µV/°C)

1.0

1.4

0

1

2

3

4

5

–1.0 –0.6 –0.2 0.2

INPUT OFFSET VOLTAGE DRIFT (µV/°C)

TIME (MINUTES)

1677 G37

1677 G02

1677 G13

1677fa

8

LT1677

U W

TYPICAL PERFOR A CE CHARACTERISTICS

Common Mode Range

vs Temperature

Long-Term Stability of Four

Representative Units

V

vs Temperature of

OS

Representative Units

140

120

100

80

5

4

2.5

2.0

250

200

150

100

50

V

= ±15V

V

S

= ±2.5V TO ±15V

S

= 0V

CM

SO-8

N8

3

1.5

125°C

2

1.0

25°C

60

–55°C

1

0.5

–55°C

40

0

20

–1

–2

–3

–4

–5

–0.5

–1.0

–1.5

–2.0

–2.5

–50

–100

–150

–200

–250

0

V

IS REFERRED 125°C

OS

–20

–40

–60

–80

TO V = 0V

CM

25°C

–

+

–55

–35 –15

5

25 45 65 85 105 125

–1.0

V

1.0 2.0 –0.8 –0.4

–

V

0.4

0

100 200 300 400 500 600 700 800 900

TIME (HOURS)

TEMPERATURE (°C)

+

V

– V (V)

V

– V (V)

CM S

CM

S

1677 G11

1677 G14

1677 G12

Common Mode Rejection Ratio

vs Frequency

Power Supply Rejection Ratio

vs Frequency

Supply Current vs Supply Voltage

4

3

2

1

160

140

120

100

V

T

= ±15V

V

T

CM

= ±15V

S

A

S

A

V

= 25°C

140

120

100

80

= 0V

T

= 125°C

= 25°C

A

T

A

NEGATIVE SUPPLY

80

60

POSITIVE SUPPLY

T

A

= –55°C

60

40

20

0

40

20

0

10

100

10k

1

100k 1M

1k

0

±5

±10

±15

±20

1k

10k

100k

1M

10M

FREQUENCY (Hz)

SUPPLY VOLTAGE (V)

FREQUENCY (Hz)

1677 G16

1677 G17

1677 G15

Voltage Gain vs Supply Voltage

(Single Supply)

Voltage Gain vs Frequency

Overshoot vs Load Capacitance

100

10

180

140

100

60

50

40

30

20

10

0

T

R

V

= 25°C

V

T

= ±15V

= 25°C

V

T

= ±15V

A

L

S

TO GND

: V = V /2

= 25°C

A

R

= 10k TO 2k

CM

O

S

L

R

= 10k

= 2k

L

V

CM

= 0V

RISING

EDGE

V

CM

= V

V

= V

EE

CC

CM

R

L

1

FALLING

EDGE

20

0.1

–20

0

10

20

30

0.01

1

100

10k

1M

100M

10

100

CAPACITANCE (pF)

1000

SUPPLY VOLTAGE (V)

FREQUENCY (Hz)

1677 G21

1677 G19

1677 G18

1677fa

9

LT1677

TYPICAL PERFOR A CE CHARACTERISTICS

U W

Large-Signal Transient Response

Small-Signal Transient Response

PM, GBWP, SR vs Temperature

70

60

50

3

V

C

= ±15V

= 15pF

S

L

PHASE

50mV

0

10V

8

7

6

5

4

GBW

–10V

–50mV

SLEW

2

A_VCL= –1

_S= ±15V

5µs/DIV

A_VCL= 1

V_S= ±15V

0.5µs/DIV

V

C_L= 15pF

1

–50

0

25

50

75 100 125

–25

TEMPERATURE (°C)

1677 G22

Settling Time vs Output Step

(Noninverting)

Settling Time vs Output Step

(Inverting)

Gain, Phase Shift vs Frequency

12

10

12

10

50

40

30

20

10

0

100

80

60

40

20

0

V

C

= ±15V

CM

= 10pF

0.01% OF

FULL SCALE

S

V

A

T

= ±15V

= 1

= 25°C

S

V

A

2k

5k

–

+

5k

–

= 0V

V

IN

V

L

OUT

L

V

OUT

2k

+

V

125°C

25°C

–55°C

IN

R

= 1k

8

6

8

6

0.01% OF

FULL SCALE

0.1% OF

FULL SCALE

0.01% OF

FULL SCALE

0.01% OF

FULL SCALE

GAIN

PHASE

0.1% OF

FULL SCALE

4

2

0

4

2

0

0.1% OF

FULL SCALE

0.1% OF

FULL SCALE

V

A

= ±15V

= –1

= 25°C

S

V

A

T

–10

–20

–10 –8 –6 –4 –2

0

2

4

6

8

10

–10 –8 –6 –4 –2

0

2

4

6

8

10

0.1

1

10

100

FREQUENCY (MHz)

OUTPUT STEP (V)

1677 G25

1677 G26

1677 G34

Output Voltage Swing

vs Load Current

Gain, Phase Shift vs Frequency

50

40

30

20

10

0

100

80

60

40

20

0

50

40

30

20

10

0

100

80

60

40

20

0

+V – 0

S

V

C

= ±15V

CM

= 10pF

V

C

= ±15V

CM

= 10pF

S

V = ±15V

S

–0.1

–0.2

–0.3

–0.4

–0.5

–0.6

–0.7

0.5

= –14V

= 14.7V

–55°C

125°C

L

125°C

25°C

–55°C

125°C

25°C

–55°C

25°C

PHASE

GAIN

PHASE

125°C

25°C

0.4

0.3

0.2

0.1

–55°C

–10

–20

–10

–20

–V + 0

S

0.1

1

10

100

0.1

1

10

100

–10 –8 –6 –4 –2

0

2

4

6

8

10

I

FREQUENCY (MHz)

SINK

SOURCE

FREQUENCY (MHz)

OUTPUT CURRENT (mA)

1677 G36

1677 G35

1677 G27

1677fa

10

LT1677

U W

TYPICAL PERFOR A CE CHARACTERISTICS

Total Harmonic Distortion and

Noise vs Frequency for

Noninverting Gain

Output Short-Circuit Current

vs Time

Closed-Loop Output Impedance

vs Frequency

0.1

0.01

50

40

30

20

10

100

10

V

= ±15V

Z

= 2k/15pF

S

L

–55°C

V

A

= ±15V

S

O

V

= 10V

P-P

= +1, +10, +100

25°C

MEASUREMENT BANDWIDTH

= 10Hz TO 80kHz

125°C

1

A

= 100

V

A

V

= +100

–30

–35

–40

–45

–50

0.1

25°C

0.001

0.0001

A

= 10

V

125°C

–55°C

A

= +1

V

0.01

0.001

A

= 1

V

10

100

1k

10k

100k

1M

0

2

3

1

4

20

100

1k

10k 20k

TIME FROM OUTPUT SHORT TO GND (MIN)

FREQUENCY (Hz)

1677 G29

1677 G30

1677 G28

Total Harmonic Distortion and

Noise vs Frequency for Inverting

Gain

Total Harmonic Distortion and

Noise vs Output Amplitude for

Noninverting Gain

Total Harmonic Distortion and

Noise vs Output Amplitude for

Inverting Gain

0.1

0.01

1

Z

= 2k/15pF

= ±15V

Z

L

= 2k/15pF

= ±15V

Z

= 2k/15pF

L

S

L

V

f

V

A

= ±15V

S

O

V

= 1kHz

f

= 1kHz

= 10V

P-P

= –1, –10, – 100

O

A

= +1, +10, +100

A

V

= –1, –10, –100

V

0.1

0.01

0.1

MEASUREMENT BANDWIDTH

= 10Hz TO 22kHz

MEASUREMENT BANDWIDTH

= 10Hz TO 22kHz

MEASUREMENT BANDWIDTH

= 10Hz TO 80kHz

A

V

= 100

A

= –100

V

A

V

= –100

0.01

A

V

= 10

A = –10

V

0.001

0.0001

A

= –10

V

A

= –1

A

= 1

0.001

V

A

= –1

100

V

0.0001

0.3

1

10

)

30

0.3

1

10

)

30

20

1k

10k 20k

OUTPUT SWING (V

P-P

FREQUENCY (Hz)

1677 G31

1677 G32

1677 G33

1677fa

11

LT1677

W U U

U

APPLICATIO S I FOR ATIO

General

The adjustment range with a 10kΩ pot is approximately

±2.5mV. Iflessadjustmentrangeisneeded, thesensitiv-

ityandresolutionofthenullingcanbeimprovedbyusing

a smaller pot in conjunction with fixed resistors. The

example has an approximate null range of ±200µV

(Figure 3).

The LT1677 series devices may be inserted directly into

OP-07,OP-27,OP-37andsocketswithorwithoutremoval

of external compensation or nulling components. In addi-

tion, the LT1677 may be fitted to 741 sockets with the

removal or modification of external nulling components.

10k

15V

Rail-to-Rail Operation

1

To take full advantage of an input range that can exceed

the supply, the LT1677 is designed to eliminate phase

reversal. ReferringtothephotographsshowninFigure1,

the LT1677 is operating in the follower mode (A_V= +1) at

asingle3Vsupply. TheoutputoftheLT1677clipscleanly

and recovers with no phase reversal. This has the benefit

of preventing lock-up in servo systems and minimizing

distortion components.

–

2

3

8

7

6

OUTPUT

LT1677

INPUT

+

4

–15V

1677 F02

Figure 2. Standard Adjustment

1k

Offset Voltage Adjustment

15V

4.7k

The input offset voltage of the LT1677 and its drift with

temperature are permanently trimmed at wafer

testing to a low level. However, if further adjustment of

V_OSis necessary, the use of a 10kΩ nulling potentiometer

will not degrade drift with temperature. Trimming to a

value other than zero creates a drift of (V_OS/300)µV/°C,

e.g., if V_OSis adjusted to 300µV, the change in drift will be

1µV/°C (Figure 2).

4.7k

1

–

2

3

8

LT1677

4

7

6

OUTPUT

+

–15V

1677 F03

Figure 3. Improved Sensitivity Adjustment

LT1677 Output

Input = –0.5V to 3.5V

3V

2V

1V

0V

3V

2V

1V

0V

–0.5V

1577 F01a

1577 F01b

Figure 1. Voltage Follower with Input Exceeding the Supply Voltage (V = 3V)

S

1677fa

12

LT1677

W U U

APPLICATIO S I FOR ATIO

U

Offset Voltage and Drift

As with all operational amplifiers when R_F> 2k, a pole will

be created with R_Fand the amplifier’s input capacitance,

creating additional phase shift and reducing the phase

margin.Asmallcapacitor(20pFto50pF)inparallelwithR_F

will eliminate this problem.

Thermocouple effects, caused by temperature gradients

across dissimilar metals at the contacts to the input

terminals, can exceed the inherent drift of the amplifier

unless proper care is exercised. Air currents should be

minimized, package leads should be short, the two input

leadsshouldbeclosetogetherandmaintainedatthesame

temperature.

Noise Testing

The 0.1Hz to 10Hz peak-to-peak noise of the LT1677 is

measured in the test circuit shown (Figure 6a). The fre-

quency response of this noise tester (Figure 6b) indicates

that the 0.1Hz corner is defined by only one zero. The test

time to measure 0.1Hz to 10Hz noise should not exceed

ten seconds, as this time limit acts as an additional zero to

eliminate noise contributions from the frequency band

below 0.1Hz.

Thecircuitshowntomeasureoffsetvoltageisalsousedas

the burn-in configuration for the LT1677, with the supply

voltages increased to ±20V (Figure 4).

50k*

15V

–

2

7

Measuring the typical 90nV peak-to-peak noise perfor-

mance of the LT1677 requires special test precautions:

6

100Ω* LT1677

V

OUT

+

3

V

= 1000V

OS

OUT

4

1. The device should be warmed up for at least five

minutes. As the op amp warms up, its offset voltage

changes typically 3µV due to its chip temperature

increasing 10°C to 20°C from the moment the power

suppliesareturnedon. Intheten-secondmeasurement

interval these temperature-induced effects can easily

exceed tens of nanovolts.

*RESISTORS MUST HAVE LOW

THERMOELECTRIC POTENTIAL

50k*

–15V

1677 F04

Figure 4. Test Circuit for Offset Voltage and

Offset Voltage Drift with Temperature

Unity-Gain Buffer Application

2. For similar reasons, the device must be well shielded

from air currents to eliminate the possibility of

thermoelectric effects in excess of a few nanovolts,

which would invalidate the measurements.

When R_F≤ 100Ω and the input is driven with a fast, large-

signal pulse (>1V), the output waveform will look as

shown in the pulsed operation diagram (Figure 5).

During the fast feedthrough-like portion of the output, the

input protection diodes effectively short the output to the

inputandacurrent, limitedonlybytheoutputshort-circuit

protection, will be drawn by the signal generator. With

R_F≥ 500Ω, the output is capable of handling the current

requirements (I_L≤ 20mA at 10V) and the amplifier stays

in its active mode and a smooth transition will occur.

3. Sudden motion in the vicinity of the device can also

“feedthrough” to increase the observed noise.

Current noise is measured in the circuit shown in Figure 7

and calculated by the following formula:

1/ 2

⎡

⎢

2⎤

2

)

− 130nV

e

• 101

⎥

(

)

(

no

R

F

⎣

⎦

i =

n

1MΩ 101

(

)(

)

–

2.5V/µs

OUTPUT

The LT1677 achieves its low noise, in part, by operating

the input stage at 100µA versus the typical 10µA of most

other op amps. Voltage noise is inversely proportional

while current noise is directly proportional to the square

1677fa

+

LT1677

1677 F05

Figure 5. Pulsed Operation

13

LT1677

W U U

U

APPLICATIO S I FOR ATIO

100

90

80

70

60

50

40

30

0.1µF

100k

10Ω

–

2k

*

+

22µF

LT1677

SCOPE

× 1

IN

4.3k

+

LT1001

4.7µF

R

= 1M

–

110k

2.2µF

VOLTAGE GAIN

100k

= 50,000

0.1µF

0.01

0.1

1

10

100

*DEVICE UNDER TEST

NOTE: ALL CAPACITOR VALUES ARE FOR

NONPOLARIZED CAPACITORS ONLY

24.3k

FREQUENCY (Hz)

1677 F06a

1677 F06b

Figure 6b. 0.1Hz to 10Hz Peak-to-Peak

Noise Tester Frequency Response

Figure 6a. 0.1Hz to 10Hz Noise Test Circuit

root of the input stage current. Therefore, the LT1677’s

currentnoisewillberelativelyhigh.Atlowfrequencies,the

low 1/f current noise corner frequency (≈90Hz) mini-

mizes current noise to some extent.

100k

100Ω

500k

–

LT1677

e

no

500k

+

In most practical applications, however, current noise will

not limit system performance. This is illustrated in the

Total Noise vs Source Resistance plot (Figure 8) where:

1677 F07

Figure 7

Total Noise = [(op amp voltage noise)²+ (resistor noise)²

+ (current noise R_S)²]^1/2

Three regions can be identified as a function of source

resistance:

1000

R

V

= ±15V

= 25°C

S

A

T

(i) R_S≤ 400Ω. Voltage noise dominates

SOURCE RESISTANCE = 2R

100

10

1

(ii) 400Ω ≤ R_S≤ 50k at 1kHz

400Ω ≤ R_S≤ 8k at 10Hz

Resistor noise

dominates

AT 1kHz

}

AT 10Hz

(iii) R_S> 50k at 1kHz

R_S> 8k at 10Hz

Current noise

dominates

}

RESISTOR

NOISE ONLY

ClearlytheLT1677shouldnotbeusedinregion(iii),where

total system noise is at least six times higher than the

voltage noise of the op amp, i.e., the low voltage noise

specification is completely wasted. In this region the

LT1792 or LT1793 is the best choice.

0.1

1

10

100

SOURCE RESISTANCE (kΩ)

1677 F08

Figure 8. Total Noise vs Source Resistance

1677fa

14

LT1677

W U U

APPLICATIO S I FOR ATIO

U

Rail-to-Rail Input

Rail-to-Rail Output

The LT1677 has the lowest voltage noise, offset voltage

and highest gain when compared to any rail-to-rail op

amp. The input common mode range for the LT1677 can

exceed the supplies by at least 100mV. As the common

mode voltage approaches the positive rail (+V_S– 0.7V),

the tail current for the input pair (Q1, Q2) is reduced,

which prevents the input pair from saturating (refer to the

Simplified Schematic). The voltage drop across the load

resistorsR_C1, R_C2isreducedtolessthan200mV, degrad-

ing the slew rate, bandwidth, voltage noise, offset voltage

and input bias current (the cancellation is shut off).

The rail-to-rail output swing is achieved by using transis-

tor collectors (Q28, Q29) instead of customary class A-B

emitter followers for the output stage. Referring to the

SimplifiedSchematic,theoutputNPNtransistor(Q29)sinks

the current necessary to move the output in the negative

direction. The change in Q29’s base emitter voltage is re-

flecteddirectlytothegainnode(collectorsofQ20andQ16).

For large sinking currents, the delta V_BEof Q29 can domi-

nate the gain. Figure 9 shows the change in input voltage

for a change in output voltage for different load resistors

connected between the supplies. The gain is much higher

for output voltages above ground (Q28 sources current)

since the change in base emitter voltage of Q28 is attenu-

ated by the gain in the PNP portion of the output stage.

Therefore, for positive output swings (output sourcing

current) there is hardly any change in input voltage for any

load resistance. Highest gain and best linearity is achieved

when the output is sourcing current, which is the case in

singlesupplyoperationwhentheloadisgroundreferenced.

Figure 10 shows gains for both sinking and sourcing load

currents for a worst-case load of 600Ω.

When the input common mode range goes below 1.5V

above the negative rail, the NPN input pair (Q1, Q2) shuts

off and the PNP input pair (Q8, Q9) turns on. The offset

voltage, input bias current, voltage noise and bandwidth

are also degraded. The graph of Offset Voltage Shift vs

Common Mode shows where the knees occur by display-

ing the change in offset voltage. The change-over points

aretemperaturedependent,see thegraphCommonMode

Range vs Temperature.

R_LTO 5V

R_L= 600

R_L= 1k

R

_L= 10k

R_LTO 0V

0

1

2

3

4

5

–15 –10 –5

0

5

10 15

OUTPUT VOLTAGE (V)

T_A= 25°C

V_S= 5V

T_A= 25°C

V_S= ±15V

R_L= 600Ω

R_LCONNECTED TO 0V

MEASURED ON TEKTRONIX 577 CURVE TRACER

Figure 10. Voltage Gain Single Supply

Figure 9. Voltage Gain Split Supply

1677fa

15

LT1677

U

TYPICAL APPLICATIO S

Microvolt Comparator with Hysteresis

3V Strain Gauge Amplifier

3V

10M

5%

15k

1%

R9

R8

R7

3.4Ω

7.5Ω

22.1Ω

7

R11

1k

3

2

+

–

15k

1%

1

R2

5Ω

R3

R5

698Ω

R*

6

5.49k

OUTPUT

INPUT

LT1677

4

R10

232Ω

3V

R*

+

1677 TA03

V

LT1677

OUT

POSITIVE FEEDBACK TO ONE OF THE NULLING TERMINALS

CREATES APPROXIMATELY 5µV OF HYSTERESIS. OUTPUT

CAN SINK 16mA

INPUT OFFSET VOLTAGE IS TYPICALLY CHANGED LESS THAN

5µV DUE TO THE FEEDBACK

–

R*

FOR TEMP

COMPENSATION

OF GAIN

R4

5.49k

R2

5Ω

*OMEGA SG-3/350LY11

350Ω, 1%

ALL OTHER RESISTORS 1%

R6

22.1Ω

1677 TA06

2 • R* + R6

R6

R4

R2 + (R*/2)

A

V

=

≅ 1000

(

) (

)

TRIM R11 FOR BRIDGE BALANCE

Precision High Side Current Sense

SOURCE

3V < V < 36V

S

R

IN

1k

2

–

7

R

LINE

0.1Ω

6

ZETEX

LT1677

4

BC856B

3

+

V

OUT

R

OUT

V

R

OUT

LOAD

OUT

20k

= R

LINE

I

R

LOAD

IN

= 2V/AMP

1677 TA07

1677fa

16

LT1677

U

TYPICAL APPLICATIO S

3V Super Electret Microphone Amplifier with DC Servo

1.5V

2N3906

1.5V

2N3906

C1

10pF

C3

0.022µF

7Hz POLE FOR SERVO

R5

2k

1.5V

7

16kHz

ROLL OFF

R1

R3

1M

–

+

2

3

6

LT1677

4

1.5V

7

–

2

3

6

–1.5V

LT1677

+

4

R2

80k

C2

100pF

–1.5V

20kHz

ROLL OFF

C4

1µF

1.5V

R4

8k

–

2

3

PANASONIC

ELECTRET

TO

7

HEADPHONES

6

CONDENSER

MICROPHONE

WM-61

LT1677

+

4

(714) 373-7334

–1.5V

1677 TA05

1677fa

17

LT1677

W

SI PLIFIED SCHE ATIC

+

1677fa

18

LT1677

U

PACKAGE DESCRIPTIO

Dimensions in inches (millimeters) unless otherwise noted.

N8 Package

8-Lead PDIP (Narrow 0.300)

(LTC DWG # 05-08-1510)

.400*

(10.160)

MAX

8

7

6

5

4

.255 ± .015*

(6.477 ± 0.381)

1

2

3

.130 ± .005

.300 – .325

.045 – .065

(3.302 ± 0.127)

(1.143 – 1.651)

(7.620 – 8.255)

.065

(1.651)

TYP

.008 – .015

(0.203 – 0.381)

.120

.020

(0.508)

MIN

(3.048)

MIN

+.035

.325

–.015

.018 ± .003

(0.457 ± 0.076)

.100

(2.54)

BSC

+0.889

8.255

(

)

N8 1002

–0.381

NOTE:

INCHES

1. DIMENSIONS ARE

MILLIMETERS

*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.

MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm)

S8 Package

8-Lead Plastic Small Outline (Narrow 0.150)

(LTC DWG # 05-08-1610)

.189 – .197

(4.801 – 5.004)

.045 ±.005

.160 ±.005

NOTE 3

.050 BSC

7

5

8

6

.245

MIN

.150 – .157

(3.810 – 3.988)

NOTE 3

.228 – .244

(5.791 – 6.197)

.030 ±.005

TYP

1

3

4

2

RECOMMENDED SOLDER PAD LAYOUT

.010 – .020

(0.254 – 0.508)

× 45°

.053 – .069

(1.346 – 1.752)

.004 – .010

(0.101 – 0.254)

.008 – .010

(0.203 – 0.254)

0°– 8° TYP

.016 – .050

(0.406 – 1.270)

.050

(1.270)

BSC

.014 – .019

(0.355 – 0.483)

TYP

NOTE:

INCHES

1. DIMENSIONS IN

(MILLIMETERS)

2. DRAWING NOT TO SCALE

3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.

MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)

SO8 0303

1677fa

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.

19

LT1677

U

TYPICAL APPLICATIO

This 2-wire remote Geophone preamp operates on a

current-loop principle and so has good noise immunity.

Quiescent current is ≈10mA for a V_OUTof 2.5V. Excitation

will cause AC currents about this point of ~±4mA for a

gain of ~107. Components R5 and Q1 convert the voltage

into a current for transmission back to R10, which con-

verts it into a voltage again. The LM334 and 2N3904 are

not temperature compensated so the DC output contains

temperature information.

V

_OUTof ~±1V max. The op amp is configured for a voltage

2-Wire Remote Geophone Preamp

R9

20Ω

+

V

LINEAR

TECHNOLOGY

LM334Z

R

–

R8

11Ω

6mA

Q1

12V

3V

2N3904

R2

R6

C

100k

R4

4.99k

+

R

C3

14k

LT1431CZ

220µF

R7

24.9k

A

R5

243Ω

V

R1

365Ω

OUT

2.5V ±1V

²–

C2

0.1µF

R10

250Ω

7

LT1677

4

GEOSPACE

GS-20DX

L

–

+

6

R

= 630Ω

3

+

GEOPHONE

www.geospacecorp.com/default.htm

C4

R3

16.2k

(713) 939-7093

1000pF

1677 TA04

||

R2 + R3 R4

≅ 107

A

=

V

R1 + R

L

RELATED PARTS

PART NUMBER

LT1028/LT1128

LT1115

DESCRIPTION

Ultralow Noise Precision Op Amps

Ultralow Noise, Low distortion Audio Op Amp

Dual/Quad Low Noise, High Speed Precision Op Amps

COMMENTS

Lowest Noise 0.85nV/√Hz

0.002% THD, Max Noise 1.2nV/√Hz

Similar to LT1007

LT1124/LT1125

LT1126/LT1127

LT1226

Dual/Quad Decompensated Low Noise, High Speed Precision Op Amps

Low Noise, Very High Speed Op Amp

Similar to LT1037

1GHz, 2.6nV/√Hz, Gain of 25 Stable

Precision C-Load^TMStable

4.2nV/√Hz, 10fA/√Hz

LT1498/LT1499

LT1792

10MHz, 5V/µs, Dual/Quad Rail-to-Rail Input and Output Op Amps

Low Noise, Precision JFET Input Op Amp

LT1793

Low Noise, Picoampere Bias Current Op Amp

6nV/√Hz, 1fA/√Hz, I = 10pA Max

B

LT1806

Low Noise, 325MHz Rail-to-Rail Input and Output Op Amp

Dual/Quad Rail-to-Rail Output Picoamp Input Precision Op Amps

3.5nV/√Hz

LT1881/LT1882

LT1884/LT1885

C

to 1000pF, I = 200pA Max

LOAD B

2.2MHz Bandwidth, 1.2V/µs SR

C-Load is a trademark of Linear Technology Corporation.

1677fa

LT 0306 REV A • PRINTED IN USA

LinearTechnology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

20

●

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


型号：	LT1677IS8#PBF
厂家：	Linear
描述：	暂无描述运算放大器
文件：	总20页 (文件大小：540K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

LT1677IS8#PBF [Linear]

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