Datasheet LT1356, LT1355 Datasheet (Linear Technology)

FEATURES

■

12MHz Gain Bandwidth

■

400V/µs Slew Rate

■

1.25mA Maximum Supply Current per Amplifier

■

Unity-Gain Stable

■

C-LoadTM Op Amp Drives All Capacitive Loads

■

10nV/√Hz Input Noise Voltage

■

800µV Maximum Input Offset Voltage

■

300nA Maximum Input Bias Current

■

70nA Maximum Input Offset Current

■

12V/mV Minimum DC Gain, RL=1k

■

230ns Settling Time to 0.1%, 10V Step

■

280ns Settling Time to 0.01%, 10V Step

■

±12.5V Minimum Output Swing into 500Ω

■

±3V Minimum Output Swing into 150Ω

■

Specified at ±2.5V, ±5V, and ±15V

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APPLICATIO S

■

Wideband Amplifiers

■

Buffers

■

Active Filters

■

Data Acquisition Systems

■

Photodiode Amplifiers

LT1355/LT1356

Dual and Quad

12MHz, 400V/µs Op Amps

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DESCRIPTIO

The LT1355/LT1356 are dual and quad low power high speed operational amplifiers with outstanding AC and DC performance. The amplifiers feature much lower supply current and higher slew rate than devices with comparable bandwidth. The circuit topology is a voltage feedback amplifier with matched high impedance inputs and the slewing performance of a current feedback amplifier. The high slew rate and single stage design provide excellent settling characteristics which make the circuit an ideal choice for data acquisition systems. Each output drives a 500Ω load to ±12.5V with ±15V supplies and a 150Ω load to ±3V on ±5V supplies. The amplifiers are stable with any capacitive load making them useful in buffer applications.

The LT1355/LT1356 are members of a family of fast, high performance amplifiers using this unique topology and employing Linear Technology Corporation’s advanced bipolar complementary processing. For a single amplifier version of the LT1355/LT1356 see the LT1354 data sheet. For higher bandwidth devices with higher supply currents see the LT1357 through LT1365 data sheets. Bandwidths of 25MHz, 50MHz, and 70MHz are available with 2mA, 4mA, and 6mA of supply current per amplifier. Singles, duals, and quads of each amplifier are available.

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

C-Load is a trademark of Linear Technology Corporation.

TYPICAL APPLICATIO

100kHz, 4th Order Butterworth Filter

6.81k

100pF

V

IN

11.3k6.81k

330pF

–

1/2

LT1355

+

5.23k

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10.2k

1000pF

5.23k

–

LT1355

+

1/2

47pF

V

1355/1356 TA01

AV = –1 Large-Signal Response

OUT

1355/1356 TA02

1

LT1355/LT1356

V

+

D

14 13 12 11 10

9 87

6

5

4

3

2

1OUT A –IN A +IN A

+IN B –IN B

OUT B OUT C

V

–

–IN D

OUT D

TOP VIEW

A

+IN D

+IN C –IN C

C

B

N PACKAGE

14-LEAD PDIP

8 7 6 54

3

2

1 –IN A +IN A

V

+

TOP VIEW

N8 PACKAGE 8-LEAD PDIP

OUT A

OUT B

V

–

–IN B +IN B

A

B

WW

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ABSOLUTE MAXIMUM RATINGS

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(Note 1)

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

Differential Input Voltage

(Transient Only) (Note 2)................................... ±10V

Input Voltage ............................................................±V

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

U

W

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PACKAGE/ORDER INFORMATION

ORDER PART

NUMBER

LT1355CN8

= 150°C, θJA = 130°C/ W

JMAX

ORDER PART

NUMBER

Operating Temperature Range (Note 7) .. –40°C to 85°C Specified Temperature Range (Note 8)... – 40°C to 85°C Maximum Junction Temperature (See Below)

S

Plastic Package ................................................150°C

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

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

TOP VIEW

+

1

OUT A

2

–IN A

+IN A

–

V

OUT A

–IN A +IN A

+

V +IN B –IN B

OUT B OUT C

A

3

S8 PACKAGE

8-LEAD PLASTIC SO

T

= 150°C, θJA = 190°C/ WT

JMAX

TOP VIEW

1 2

A

3 4 5

B

6

8

V

7

OUT B

6

–IN B

B

+IN B

54

16

OUT D

15

–IN D

D

+IN D

14

–

13

V

12

+IN C

C

11

–IN C

107

98NC NC

ORDER PART

NUMBER

LT1355CS8

S8 PART MARKING

1355

ORDER PART

NUMBER

LT1356CSLT1356CN

= 150°C, θJA = 110°C/W

T

JMAX

Consult factory for Industrial and Military grade parts.

ELECTRICAL CHARACTERISTICS

SYMBOL PARAMETER CONDITIONS V

V

OS

I

OS

I

B

e

n

i

n

R

IN

C

IN

2

Input Offset Voltage ±15V 0.3 0.8 mV

Input Offset Current ±2.5V to ±15V 20 70 nA Input Bias Current ±2.5V to ±15V 80 300 nA Input Noise Voltage f = 10kHz ±2.5V to ±15V 10 nV/√Hz Input Noise Current f = 10kHz ±2.5V to ±15V 0.6 pA/√Hz Input Resistance V Input Resistance Differential ±15V 11 MΩ Input Capacitance ±15V 3 pF

S PACKAGE

16-LEAD PLASTIC SO

T

= 150°C, θJA = 150°C/W

JMAX

T

= 25°C, V

A

= 0V unless otherwise noted.

CM

SUPPLY

MIN TYP MAX UNITS

±5V 0.3 0.8 mV ±2.5V 0.4 1.0 mV

= ±12V ±15V 70 160 MΩ

CM

ELECTRICAL CHARACTERISTICS

T

= 25°C, V

A

= 0V unless otherwise noted.

CM

LT1355/LT1356

SYMBOL PARAMETER CONDITIONS V

Input Voltage Range

+

SUPPLY

±15V 12.0 13.4 V

MIN TYP MAX UNITS

±5V 2.5 3.5 V ±2.5V 0.5 1.1 V

Input Voltage Range

–

±15V –13.2 –12.0 V ±5V –3.4 –2.5 V ±2.5V –0.9 –0.5 V

CMRR Common Mode Rejection Ratio V

= ±12V ±15V 83 97 dB

CM

= ±2.5V ±5V 78 84 dB

V

CM

= ±0.5V ±2.5V 68 75 dB

V

CM

PSRR Power Supply Rejection Ratio VS = ±2.5V to ±15V 92 106 dB A

V

I

VOL

OUT

SC

Large-Signal Voltage Gain V

= ±12V, RL = 1k ±15V 12 36 V/mV

OUT

= ±10V, RL = 500Ω±15V 5 15 V/mV

V

OUT

= ±2.5V, RL = 1k ±5V 12 36 V/mV

V

OUT

V

= ±2.5V, RL = 500Ω±5V 5 15 V/mV

OUT

= ±2.5V, RL = 150Ω±5V 1 4 V/mV

V

OUT

= ±1V, RL = 500Ω±2.5V 5 20 V/mV

V

OUT

Output Swing RL = 1k, V

R

= 500Ω, V

L

= 500Ω, V

R

L

= 150Ω, V

R

L

RL = 500Ω, V

Output Current V

Short-Circuit Current V

= ±12.5V ±15V 25 30 mA

OUT

= ±3V ±5V 20 25 mA

V

OUT

= 0V, V

OUT

= ±40mV ±15V 13.3 13.8 ±V

IN

= ±40mV ±15V 12.5 13.0 ±V

IN

= ±40mV ±5V 3.5 4.0 ±V

IN

= ±40mV ±5V 3.0 3.3 ±V

IN

= ±40mV ±2.5V 1.3 1.7 ±V

IN

= ±3V ±15V 30 42 mA

IN

SR Slew Rate AV = – 2, (Note 4) ±15V 200 400 V/µs

±5V 70 120 V/µs

Full Power Bandwidth 10V Peak, (Note 5) ±15V 6.4 MHz

3V Peak, (Note 5) ±5V 6.4 MHz

GBW Gain Bandwidth f = 200kHz, RL = 2k ±15V 9.0 12.0 MHz

±5V 7.5 10.5 MHz ±2.5V 9.0 MHz

tr, t

f

Rise Time, Fall Time AV = 1, 10%-90%, 0.1V ±15V 14 ns

±5V 17 ns

Overshoot AV = 1, 0.1V ±15V 20 %

±5V 18 %

Propagation Delay 50% VIN to 50% V

, 0.1V ±15V 16 ns

OUT

±5V 19 ns

t

s

Settling Time 10V Step, 0.1%, AV = –1 ±15V 230 ns

10V Step, 0.01%, A 5V Step, 0.1%, A 5V Step, 0.01%, A

= –1 ±15V 280 ns

V

= –1 ±5V 240 ns

V

= –1 ±5V 380 ns

V

Differential Gain f = 3.58MHz, AV = 2, RL = 1k ±15V 2.2 %

±5V 2.1 %

Differential Phase f = 3.58MHz, AV = 2, RL = 1k ±15V 3.1 Deg

±5V 3.1 Deg

R

O

I

S

Output Resistance AV = 1, f = 100kHz ±15V 0.7 Ω Channel Separation V

= ±10V, RL = 500Ω±15V 100 113 dB

OUT

Supply Current Each Amplifier ±15V 1.0 1.25 mA

Each Amplifier ±5V 0.9 1.20 mA

3

LT1355/LT1356

ELECTRICAL CHARACTERISTICS

0°C ≤ TA ≤ 70°C, V

SYMBOL PARAMETER CONDITIONS V

V

OS

Input Offset Voltage ±15V ● 1.0 mV

= 0V unless otherwise noted.

CM

The ● denotes the specifications which apply over the temperature range

SUPPLY

±5V ±2.5V

MIN TYP MAX UNITS

● 1.0 mV

● 1.2 mV

Input VOS Drift (Note 6) ±2.5V to ±15V ● 58 µV/°C

I

OS

I

B

CMRR Common Mode Rejection Ratio V

Input Offset Current ±2.5V to ±15V ● 100 nA Input Bias Current ±2.5V to ±15V ● 450 nA

= ±12V ±15V ● 81 dB

CM

= ±2.5V ±5V ● 77 dB

V

CM

= ±0.5V ±2.5V ● 67 dB

V

CM

PSRR Power Supply Rejection Ratio VS = ±2.5V to ±15V ● 90 dB A

V

I

VOL

OUT

SC

Large-Signal Voltage Gain V

= ±12V, RL = 1k ±15V ● 10.0 V/mV

OUT

= ±10V, RL = 500Ω±15V ● 3.3 V/mV

V

OUT

= ±2.5V, RL = 1k ±5V ● 10.0 V/mV

V

OUT

V

= ±2.5V, RL = 500Ω±5V ● 3.3 V/mV

OUT

= ±2.5V, RL = 150Ω±5V ● 0.6 V/mV

V

OUT

= ±1V, RL = 500Ω±2.5V ● 3.3 V/mV

V

OUT

Output Swing RL = 1k, V

R

= 500Ω, V

L

= 500Ω, V

R

L

= 150Ω, V

R

L

R

= 500Ω, V

L

Output Current V

Short-Circuit Current V

= ±12V ±15V ● 24.0 mA

OUT

= ±2.8V ±5V ● 18.7 mA

V

OUT

= 0V, V

OUT

= ±40mV ±15V ● 13.2 ±V

IN

= ±40mV ±15V ● 12.0 ±V

IN

= ±40mV ±5V ● 3.4 ±V

IN

= ±40mV ±5V ● 2.8 ±V

IN

= ±40mV ±2.5V ● 1.2 ±V

IN

= ±3V ±15V ● 24 mA

IN

SR Slew Rate AV = –2, (Note 4) ±15V ● 150 V/µs

±5V

● 60 V/µs

GBW Gain Bandwidth f = 200kHz, RL = 2k ±15V ● 7.5 MHz

±5V

Channel Separation V

I

S

Supply Current Each Amplifier ±15V ● 1.45 mA

= ±10V, RL = 500Ω±15V ● 98 dB

OUT

● 6.0 MHz

Each Amplifier ±5V ● 1.40 mA

The ● denotes the specifications which apply over the temperature range – 40°C ≤ TA ≤ 85°C, V

SYMBOL PARAMETER CONDITIONS V

V

OS

Input Offset Voltage ±15V ● 1.5 mV

SUPPLY

±5V ±2.5V

= 0V unless otherwise noted. (Note 8)

CM

MIN TYP MAX UNITS

● 1.5 mV

● 1.7 mV

Input VOS Drift (Note 6) ±2.5V to ±15V ● 58 µV/°C

I

OS

I

B

CMRR Common Mode Rejection Ratio V

Input Offset Current ±2.5V to ±15V ● 200 nA Input Bias Current ±2.5V to ±15V ● 550 nA

= ±12V ±15V ● 80 dB

CM

= ±2.5V ±5V ● 76 dB

V

CM

= ±0.5V ±2.5V ● 66 dB

V

CM

PSRR Power Supply Rejection Ratio VS = ±2.5V to ±15V ● 90 dB A

VOL

Large-Signal Voltage Gain V

= ±12V, RL = 1k ±15V ● 7.0 V/mV

OUT

= ±10V, RL = 500Ω±15V ● 1.7 V/mV

V

OUT

= ±2.5V, RL = 1k ±5V ● 7.0 V/mV

V

OUT

V

= ±2.5V, RL = 500Ω±5V ● 1.7 V/mV

OUT

4

LT1355/LT1356

ELECTRICAL CHARACTERISTICS

–40°C ≤ TA ≤ 85°C, V

SYMBOL PARAMETER CONDITIONS V

V

I

OUT

SC

Output Swing RL = 1k, V

Output Current V

Short-Circuit Current V

= 0V unless otherwise noted. (Note 8)

CM

V

= ±2.5V, RL = 150Ω±5V ● 0.4 V/mV

OUT

V

= ±1V, RL = 500Ω±2.5V ● 1.7 V/mV

OUT

= 500Ω, V

R

L

R

= 500Ω, V

L

= 150Ω, V

R

L

= 500Ω, V

R

L OUT

V

OUT OUT

The ● denotes the specifications which apply over the temperature range

SUPPLY

= ±40mV ±15V ● 13.0 ±V

IN

= ±40mV ±15V ● 11.5 ±V

IN

= ±40mV ±5V ● 3.4 ±V

IN

= ±40mV ±5V ● 2.6 ±V

IN

= ±40mV ±2.5V ● 1.2 ±V

IN

= ±11.5V ±15V ● 23.0 mA = ±2.6V ±5V ● 17.3 mA

= 0V, V

= ±3V ±15V ● 23 mA

IN

MIN TYP MAX UNITS

SR Slew Rate AV = –2, (Note 4) ±15V ● 120 V/µs

±5V

● 50 V/µs

GBW Gain Bandwidth f = 200kHz, RL = 2k ±15V ● 7.0 MHz

±5V

Channel Separation V

I

S

Supply Current Each Amplifier ±15V ● 1.50 mA

= ±10V, RL = 500Ω±15V ● 98 dB

OUT

● 5.5 MHz

Each Amplifier ±5V ● 1.45 mA

Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired.

Note 2: Differential inputs of ±10V are appropriate for transient operation only, such as during slewing. Large, sustained differential inputs will cause excessive power dissipation and may damage the part. See Input Considerations in the Applications Information section of this data sheet for more details.

Note 3: A heat sink may be required to keep the junction temperature below absolute maximum when the output is shorted indefinitely.

Note 4: Slew rate is measured between ±10V on the output with ±6V input

Note 5: Full power bandwidth is calculated from the slew rate

measurement: FPBW = (SR)/2πV

.

P

Note 6: This parameter is not 100% tested. Note 7: The LT1355C/LT1356C are guaranteed functional over the

operating temperature range of –40°C to 85°C. Note 8: The LT1355C/LT1356C are guaranteed to meet specified

performance from 0°C to 70°C. The LT1355C/LT1356C 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. For guaranteed I-grade parts, consult the factory.

for ±15V supplies and ±1V on the output with ±1.75V input for ±5V supplies.

W

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TYPICAL PERFORMANCE CHARACTERISTICS

Supply Current vs Supply Voltage and Temperature

1.4

1.2

1.0

0.8

SUPPLY CURRENT (mA)

0.6

0.4 10501520

SUPPLY VOLTAGE (±V)

125°C

25°C

–55°C

1355/1356 G01

Input Common Mode Range vs Supply Voltage

+

V

TA = 25°C

–0.5

–1.0 –1.5 –2.0

2.0

1.5

COMMON MODE RANGE (V)

1.0

0.5

–

V

< 1mV

∆V

OS

SUPPLY VOLTAGE (±V)

10501520

1355/1356 G02

Input Bias Current vs Input Common Mode Voltage

200

VS = ±15V

= 25°C

T

A

+

–

I

150

100

50

INPUT BIAS CURRENT (nA)

0

–50

–15 –10 0 10 155–5

+ I

B

I

B

=

————

 

2

INPUT COMMON MODE VOLTAGE (V)

1355/1356 G03

5

LT1355/LT1356

W

U

TYPICAL PERFORMANCE CHARACTERISTICS

Input Bias Current vs Temperature

200

175

150

125

100

75

50

INPUT BIAS CURRENT (nA)

25

0

–50 –25 25 100 12550 750

TEMPERATURE (°C)

VS = ±15V

=

I

B

Open-Loop Gain vs Temperature

97

VS = ±15V

96

= 1k

R

L

= ±12V

V

95

O

94

93

92

91

OPEN-LOOP GAIN (dB)

90

89

88

–50 –25 25 100 12550 750

TEMPERATURE (°C)

+

–

I

+ I

B

————

 

2

1355/1356 G04

1355/1356 G07

Input Noise Spectral Density

100

e

n

1k100 100k10k

FREQUENCY (Hz)

INPUT VOLTAGE NOISE (nV/√Hz)

i

10

1

10

Output Voltage Swing vs Supply Voltage

+

V

TA = 25°C

–1

–2

–3

3

2

OUTPUT VOLTAGE SWING (V)

1

–

V

R

SUPPLY VOLTAGE (±V)

Open-Loop Gain vs Resistive Load

100

INPUT CURRENT NOISE (pA/√Hz)

90

80

70

OPEN-LOOP GAIN (dB)

60

50

= 25°C

T

A

10

LOAD RESISTANCE (Ω)

VS = ±15V

= 25°C

T

A

= 101

A

V

R

= 100k

S

1355/1356 G05

10

1

0.1

Output Voltage Swing vs Load Current

+

–0.5

V

RL = 1k

= 500Ω

L

R

= 500Ω

L

R

= 1k

L

10501520

1355/1356 G08

–

V

VS = ±5V

–1.0 –1.5 –2.0 –2.5

2.5

2.0

OUTPUT VOLTAGE SWING (V)

1.5

1.0

+ 0.5

= 100mV

V

IN

–40°C

–50 –40 –10 30 40 5001020–20–30

85°C

OUTPUT CURRENT (mA)

VS = ±15V

VS = ±5V

100 10k

1k

1355/1356 G06

85°C

–40°C

25°C

1355/1356 G09

Output Short-Circuit Current vs Temperature

65

60

55

50 45

40

35

30

25

OUTPUT SHORT-CIRCUIT CURRENT (mA)

20

–50 –25 25 100 12550 750

SOURCE

TEMPERATURE (°C)

SINK

6

VS = ±5V

1355/1356 G10

Settling Time vs Output Step (Noninverting)

10

VS = ±15V

8

A

= 1

V

6

10mV

4 2 0

–2

OUTPUT SWING (V)

–4 –6 –8

–10

10mV

50 200 300 350250100 150

SETTLING TIME (ns)

1mV

1355/1356 G11

Settling Time vs Output Step (Inverting)

10

VS = ±15V

8

= –1

A

V

6 4

10mV

2 0

–2

OUTPUT SWING (V)

–4 –6 –8

–10

50 200 300 350250100 150

SETTLING TIME (ns)

1mV

10mV

1mV

1355/1356 G12

W

SUPPLY VOLTAGE (±V)

8

GAIN BANDWIDTH (MHz)

12

10

18

16

14

11

9

17

15

13

30

PHASE MARGIN (DEG)

38

34

50 48

44

40

36

32

46

42

10501520

1355/1356 G15

TA = 25°C

PHASE MARGIN

GAIN BANDWIDTH

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TYPICAL PERFORMANCE CHARACTERISTICS

LT1355/LT1356

Output Impedance vs Frequency

1k

AV = 100

100

10

AV = 10

OUTPUT IMPEDANCE (Ω)

0.1

0.01

1

10k

AV = 1

100k 100M

1M

FREQUENCY (Hz)

Gain Bandwidth and Phase Margin vs Temperature

18 17 16 15 14

13 12 11

GAIN BANDWIDTH (MHz)

10

GAIN BANDWIDTH V

S

9 8

–50 –25 25 100 12550 750

= ±5V

PHASE MARGIN

= ±15V

V

S

PHASE MARGIN

= ±5V

V

S

GAIN BANDWIDTH

= ±15V

V

S

TEMPERATURE (°C)

VS = ±15V

= 25°C

T

A

10M

1355/1356 G13

1355/1356 G16

Frequency Response vs Capacitive Load

10

VS = ±15V

8

= 25°C

T

A

= –1

6

V

4 2

0

–2

–4

VOLTAGE MAGNITUDE (dB)

–6 –8

–10

100k

52 50 48

PHASE MARGIN (DEG)

46

44 42

40

38 36 34

32

5 4 3 2 1

0

GAIN (dB)

–1 –2

–3 –4 –5

100k

C = 1000pF

C = 500pF

C = 100pF

C = 50pF

C = 0

1M 100M10M

FREQUENCY (Hz)

Frequency Response vs Supply Voltage (AV = 1)

T

= 25°C

A

= 1

A

V

R

= 2k

L

±5V

±2.5V

1M 100M

FREQUENCY (Hz)

10M

1355/1356 G19

±15V

1355/1356 G17

Gain Bandwidth and Phase Margin vs Supply Voltage

Frequency Response vs Supply Voltage (AV = –1)

5

T

= 25°C

A

4

= –1

A

V

= RG = 2k

R

3

F

2 1

0

GAIN (dB)

–1 –2

–3 –4 –5

100k

±2.5V

1M 100M

FREQUENCY (Hz)

±5V

±15V

10M

1355/1356 G18

Gain and Phase vs Frequency

70

60

50

40

30

GAIN (dB)

20

10

0

–10

10k

120

PHASE

VS = ±15V

GAIN

VS = ±5V

= 25°C

T

A

= –1

A

V

= RG = 2k

R

F

100k 100M

FREQUENCY (Hz)

VS = ±5V

1M

10M

100

PHASE (DEG)

80

60

40

20

0

1355/1356 G14

Power Supply Rejection Ratio vs Frequency

100

80

60

40

20

POWER SUPPLY REJECTION RATIO (dB)

0

+PSRR

–PSRR

100k 1M1k 10k100 10M 100M

FREQUENCY (Hz)

VS = ±15V

= 25°C

T

A

1355/1356 G20

Common Mode Rejection Ratio vs Frequency

120

100

80

60

40

20

COMMON-MODE REJECTION RATIO (dB)

0

1k 100M10M1M100k10k

FREQUENCY (Hz)

VS = ±15V

= 25°C

T

A

1355/1356 G21

7

LT1355/LT1356

INPUT LEVEL (V

P-P

)

0

SLEW RATE (V/µs)

100

500

400

200

300

0 8 16 2012421018146

1355/1356 G24

TA = 25°C V

S

= ±15V

A

V

= –1

R

F

= RG = 2k

SR =

SR

+

+ SR

–

—————

2

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TYPICAL PERFORMANCE CHARACTERISTICS

Slew Rate vs Supply Voltage

600

TA = 25°C

= –1

A

V

500

= RG = 2k

R

F

+

–

+ SR

SR

SR =

—————

400

300

200

SLEW RATE (V/µs)

100

0

015105

2

SUPPLY VOLTAGE (±V)

Total Harmonic Distortion vs Frequency

0.1 TA = 25°C

V

= 3V

O

RMS

RL = 2k

0.01

AV = –1

0.001

AV = 1

TOTAL HARMONIC DISTORTION (%)

0.0001 10

100 100k

1k

FREQUENCY (Hz)

10k

1355/1356 G22

1355/1356 G25

Slew Rate vs Temperature

350

300

250

200

150

SLEW RATE (V/µs)

100

50

= –2

A

V

SR+ + SR

SR = —————

–50 –25 25 100 12550 750

–

2

TEMPERATURE (°C)

Undistorted Output Swing vs

Frequency (±15V)

30

25

)

P-P

20

15

VS = ±15V

10

R

= 5k

L

= 1,

A

OUTPUT VOLTAGE (V

V

1% MAX DISTORTION

5

= –1,

A

V

4% MAX DISTORTION

0

100k 1M

FREQUENCY (Hz)

AV = 1

V

= ±15V

S

V

S

AV = –1

= ±5V

1355/1356 G23

10M

1355/1356 G26

Slew Rate vs Input Level

Undistorted Output Swing vs

Frequency (±5V)

10

8

)

P-P

6

4

VS = ±5V R

L

A

OUTPUT VOLTAGE (V

V

2% MAX DISTORTION

2

A

V

3% MAX DISTORTION

0

100k 1M

= 5k = 1,

= –1,

AV = 1

FREQUENCY (Hz)

AV = –1

10M

1355/1356 G27

2nd and 3rd Harmonic Distortion vs Frequency

–20

VS = ±15V

= 2V

V

O

–30

–40

–50

–60

HARMONIC DISTORTION (dB)

–70

–80

100k 200k 400k

8

P-P

RL = 2k

= 2

A

V

3RD HARMONIC

2ND HARMONIC

1M 2M 4M

FREQUENCY (Hz)

1355/1356 G28

10M

Crosstalk vs Frequency

–40

TA = 25°C

–50

–60

–70

–80

–90

CROSSTALK (dB)

–100

–110

–120

100k

V

IN

R

L

A

V

= 0dBm

= 500Ω = 1

1M 100M

FREQUENCY (Hz)

10M

1355/1356 G29

Capacitive Load Handling

100

TA = 25°C

= ±15V

V

S

AV = 1

50

OVERSHOOT (%)

0

10p

1000p 0.01µ

100p 0.1µ

CAPACITIVE LOAD (F)

AV = –1

1µ

1355/1356 G30

W

U

TYPICAL PERFORMANCE CHARACTERISTICS

LT1355/LT1356

Small-Signal Transient (AV = 1)

Large-Signal Transient (AV = 1)

1355/1356 G31

Small-Signal Transient (AV = –1)

Large-Signal Transient (AV = –1)

1355/1356 G32

Small- Signal Transient (AV = –1, CL = 1000pF)

1355/1356 G33

Large-Signal Transient (AV = 1, CL = 10,000pF)

1355/1356 G34

U

WUU

APPLICATIONS INFORMATION

Layout and Passive Components

The LT1355/LT1356 amplifiers are easy to use and tolerant of less than ideal layouts. For maximum performance (for example, fast 0.01% settling) use a ground plane, short lead lengths, and RF-quality bypass capacitors (0.01µF to 0.1µF). For high drive current applications use low ESR bypass capacitors (1µF to 10µF tantalum).

The parallel combination of the feedback resistor and gain setting resistor on the inverting input combine with the input capacitance to form a pole which can cause peaking

1355/1356 G35

1355/1356 G36

or oscillations. If feedback resistors greater than 5kΩ are used, a parallel capacitor of value

CF > RG x CIN/R

F

should be used to cancel the input pole and optimize dynamic performance. For unity-gain applications where a large feedback resistor is used, CF should be greater than or equal to CIN.

9

LT1355/LT1356

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WUU

APPLICATIONS INFORMATION

Capacitive Loading

The LT1355/LT1356 are stable with any capacitive load. As the capacitive load increases, both the bandwidth and phase margin decrease so there will be peaking in the frequency domain and in the transient response. Coaxial cable can be driven directly, but for best pulse fidelity a resistor of value equal to the characteristic impedance of the cable (i.e., 75Ω) should be placed in series with the output. The other end of the cable should be terminated with the same value resistor to ground.

Input Considerations

Each of the LT1355/LT1356 inputs is the base of an NPN and a PNP transistor whose base currents are of opposite polarity and provide first-order bias current cancellation. Because of variation in the matching of NPN and PNP beta, the polarity of the input bias current can be positive or negative. The offset current does not depend on NPN/PNP beta matching and is well controlled. The use of balanced source resistance at each input is recommended for applications where DC accuracy must be maximized.

The inputs can withstand transient differential input voltages up to 10V without damage and need no clamping or source resistance for protection. Differential inputs, however, generate large supply currents (tens of mA) as required for high slew rates. If the device is used with sustained differential inputs, the average supply current will increase, excessive power dissipation will result and the part may be damaged. The part should not be used as

a comparator, peak detector or other open-loop application with large, sustained differential inputs. Under

normal, closed-loop operation, an increase of power dissipation is only noticeable in applications with large slewing outputs and is proportional to the magnitude of the differential input voltage and the percent of the time that the inputs are apart. Measure the average supply current for the application in order to calculate the power dissipation.

Circuit Operation

The LT1355/LT1356 circuit topology is a true voltage feedback amplifier that has the slewing behavior of a current feedback amplifier. The operation of the circuit can be understood by referring to the simplified schematic. The inputs are buffered by complementary NPN and PNP emitter followers which drive an 800Ω resistor. The input voltage appears across the resistor generating currents which are mirrored into the high impedance node. Complementary followers form an output stage which buffers the gain node from the load. The bandwidth is set by the input resistor and the capacitance on the high impedance node. The slew rate is determined by the current available to charge the gain node capacitance. This current is the differential input voltage divided by R1, so the slew rate is proportional to the input. Highest slew rates are therefore seen in the lowest gain configurations. For example, a 10V output step in a gain of 10 has only a 1V input step, whereas the same output step in unity gain has a 10 times greater input step. The curve of Slew Rate vs Input Level illustrates this relationship. The LT1355/ LT1356 are tested for slew rate in a gain of –2 so higher slew rates can be expected in gains of 1 and –1, and lower slew rates in higher gain configurations.

The RC network across the output stage is bootstrapped when the amplifier is driving a light or moderate load and has no effect under normal operation. When driving a capacitive load (or a low value resistive load) the network is incompletely bootstrapped and adds to the compensation at the high impedance node. The added capacitance slows down the amplifier which improves the phase margin by moving the unity-gain frequency away from the pole formed by the output impedance and the capacitive load. The zero created by the RC combination adds phase to ensure that even for very large load capacitances, the total phase lag can never exceed 180 degrees (zero phase margin) and the amplifier remains stable.

10

LT1355/LT1356

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APPLICATIONS INFORMATION

Power Dissipation

The LT1355/LT1356 combine high speed and large output drive in small packages. Because of the wide supply voltage range, it is possible to exceed the maximum junction temperature under certain conditions. Maximum junction temperature (TJ) is calculated from the ambient temperature (TA) and power dissipation (PD) as follows:

LT1355CN8: TJ = TA + (PD x 130°C/W) LT1355CS8: TJ = TA + (PD x 190°C/W) LT1356CN: TJ = TA + (PD x 110°C/W) LT1356CS: TJ = TA + (PD x 150°C/W)

WW

SI PLIFIED

SCHE ATIC

Worst case power dissipation occurs at the maximum supply current and when the output voltage is at 1/2 of either supply voltage (or the maximum swing if less than 1/2 supply voltage). For each amplifier P

P

= (V+ – V–)(I

DMAX

) + (V+/2)2/R

SMAX

DMAX

L

is:

Example: LT1356 in S16 at 70°C, VS = ±15V, RL = 1k

P

= (30V)(1.45mA) + (7.5V)2/1kW = 99.8mW

DMAX

T

= 70°C + (4 × 99.8mW)(150°C/W) = 130°C

JMAX

–IN

+

V

R1

800Ω

–

V

+IN

R

C

OUT

1355/1356 SS01

11

LT1355/LT1356

PACKAGE DESCRIPTIO

U

Dimensions in inches (millimeters) unless otherwise noted.

N8 Package

8-Lead PDIP (Narrow 0.300)

(LTC DWG # 05-08-1510)

0.400*

(10.160)

MAX

876

0.255 ± 0.015* (6.477 ± 0.381)

5

12

0.300 – 0.325

(7.620 – 8.255)

0.065

(1.651)

0.009 – 0.015

(0.229 – 0.381)

+0.035

0.325

–0.015

+0.889

8.255

()

–0.381

*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm)

TYP

0.045 – 0.065

(1.143 – 1.651)

0.100 (2.54)

BSC

3

4

0.130 ± 0.005

(3.302 ± 0.127)

0.125

(3.175)

MIN

0.018 ± 0.003

(0.457 ± 0.076)

0.020

(0.508)

MIN

N8 1098

12

PACKAGE DESCRIPTIO

U

Dimensions in inches (millimeters) unless otherwise noted.

N Package

14-Lead PDIP (Narrow 0.300)

(LTC DWG # 05-08-1510)

0.770*

(19.558)

MAX

14

0.255 ± 0.015* (6.477 ± 0.381)

11

1213

LT1355/LT1356

8910

2

0.300 – 0.325

(7.620 – 8.255)

0.009 – 0.015

(0.229 – 0.381)

+0.035

0.325

–0.015

+0.889

8.255

()

–0.381

*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm)

0.020

(0.508)

MIN

0.130 ± 0.005

(3.302 ± 0.127)

0.125

(3.175)

MIN

0.005

(0.125)

MIN

31

0.045 – 0.065

(1.143 – 1.651)

0.100

(2.54)

BSC

6

(0.457 ± 0.076)

7

0.065

(1.651)

TYP

0.018 ± 0.003

N14 1098

5

4

13

LT1355/LT1356

PACKAGE DESCRIPTIO

U

Dimensions in inches (millimeters) unless otherwise noted.

S8 Package

8-Lead Plastic Small Outline (Narrow 0.150)

(LTC DWG # 05-08-1610)

0.189 – 0.197* (4.801 – 5.004)

7

8

5

6

0.228 – 0.244

(5.791 – 6.197)

0.010 – 0.020

(0.254 – 0.508)

0.008 – 0.010

(0.203 – 0.254)

*

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

× 45°

0°– 8° TYP

0.016 – 0.050

(0.406 – 1.270)

0.053 – 0.069

(1.346 – 1.752)

0.014 – 0.019

(0.355 – 0.483)

TYP

0.150 – 0.157** (3.810 – 3.988)

1

3

2

4

0.004 – 0.010

(0.101 – 0.254)

0.050

(1.270)

BSC

SO8 1298

14

PACKAGE DESCRIPTIO

U

Dimensions in inches (millimeters) unless otherwise noted.

S Package

16-Lead Plastic Small Outline (Narrow 0.150)

(LTC DWG # 05-08-1610)

0.386 – 0.394* (9.804 – 10.008)

13

16

14

15

12

11

LT1355/LT1356

10

9

0.010 – 0.020

(0.254 – 0.508)

0.008 – 0.010

(0.203 – 0.254)

*

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

×

°

45

0.016 – 0.050

(0.406 – 1.270)

0° – 8° TYP

0.228 – 0.244

(5.791 – 6.197)

0.053 – 0.069

(1.346 – 1.752)

0.014 – 0.019

(0.355 – 0.483)

TYP

0.150 – 0.157** (3.810 – 3.988)

4

5

0.050

(1.270)

BSC

3

2

1

7

6

8

0.004 – 0.010

(0.101 – 0.254)

S16 1098

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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.

15

LT1355/LT1356

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TYPICAL APPLICATIONS

Instrumentation Amplifier

R5

432Ω

R1

20k

–

V

IN

–

LT1355

+

1/2

R2

2k

R3 2k

–

LT1355

+

1/2

R4

20k

V

OUT

+





R

4

12213423



A

=+ +

1

V

R

3





TRIM R5 FOR GAIN TRIM R1 FOR COMMON-MODE REJECTION BW = 120kHz



RRRRRR











+



+

=

104

R

5





1355/1356 TA03

100kHz, 4th Order Butterworth Filter

(Sallen-Key)

C4

C2

330pF

–

1/2

LT1355

V

IN

R1

2.87k

R2

26.7k

+

C1 100pF

R3

2.43k

1000pF

R4

15.4k

–

+

C3 68pF

1/2

LT1355

V

1355/1356 TA04

OUT

RELATED PARTS

PART NUMBER DESCRIPTION COMMENTS

LT1354 12MHz, 400V/µs Op Amp Single Version of LT1355/LT1356 LT1352/LT1353 Dual and Quad 250µA, 3MHz, 200V/µs Op Amps Lower Power Version of LT1355/LT1356, VOS = 0.6mV, IS = 250µA/Amplifier LT1358/LT1359 Dual and Quad 25MHz, 600Vµs Op Amps Faster Version of LT1355/LT1356, VOS = 0.6mV, IS = 2mA/Amplifier

13556fa LT/TP 0400 2K REV A • PRINTED IN USA

 LINEAR TECHNOLOGY CORPORATION 1994

16

Linear Technology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

(408) 432-1900 ● FAX: (408) 434-0507

●

www.linear-tech.com