FEATURES

LT1352/LT1353

Dual and Quad 250A, 3MHz, 200V/s

Operational Amplifiers

U

DESCRIPTIO

The LT®1352/LT1353 are dual and quad, very 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 combines the slewing performance of a current feedback amplifier in a true operational amplifier with matched high impedance inputs. The high slew rate ensures that the large-signal bandwidth is not degraded. Each output is capable of driving a 1kloadto 13Vwith15Vsuppliesanda 500 load to 3.4V on 5V supplies.

The LT1352/LT1353 are members of a family of fast, high performance amplifiers using this unique topology and employing Linear Technology Corporation’s advanced complementary bipolar processing. For higher bandwidth devices with higher supply current see the LT1354 through LT1365 data sheets. Bandwidths of 12MHz, 25MHz, 50MHz and 70MHz are available with 1mA, 2mA, 4mA and 6mA of supply current per amplifier. Singles, duals and quads of each amplifier are available. The LT1352 is available in an 8-lead SO package. The LT1353 is offered in a 14-lead narrow surface mount package.

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

C-Load is a trademark of Linear Technology Corporation.


U

TYPICAL APPLICATIO

Instrumentation Amplifier Large-Signal Response


R1

50k

R2

5k


1/2


R5 1.1k


R3

5k


R4

50k


LT1352

– +

1/2

LT1352


VOUT

VIN +

+

GAIN = [R4/R3][1 + (1/2)(R2/R1 + R3/R4) + (R2 + R3)/R5] = 102 TRIM R5 FOR GAIN

TRIM R1 FOR COMMON MODE REJECTION BW = 30kHz


1352/53 TA01


AV = –1 1352/53 TA02


U

W W

W

ABSOLUTE AXI U RATINGS

(Note 1)

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

Differential Input Voltage (Transient Only, Note 2) 10V Input Voltage .......................................................... VS

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

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


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

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

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

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


U

W

U

PACKAGE/ORDER I FOR ATIO



TOP VIEW

OUT A 1 8 V+

–IN A 2 7 OUT B

A

+IN A 3 6 –IN B

B

V4 5 +IN B


N8 PACKAGE 8-LEAD PDIP

S8 PACKAGE

8-LEAD PLASTIC SO


TJMAX = 150C, JA = 130C/ W (N8) TJMAX = 150C, JA = 190C/ W (S8)

ORDER PART NUMBER

TOP VIEW


OUT A 1 14 OUT D

–IN A 2 13 –IN D A D

+IN A 3 12 +IN D

V+ 4 11 V

+IN B 5 B C 10 +IN C

–IN B 6 9 –IN C

OUT B 7 8 OUT C


S PACKAGE

14-LEAD PLASTIC SO TJMAX = 150C, JA = 150C/ W

ORDER PART NUMBER

LT1352CN8 LT1352CS8 LT1352IN8 LT1352IS8

LT1353CS

S8 PART MARKING

1352

1352I

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


ELECTRICAL CHARACTERISTICS TA = 25C, VCM = 0V unless otherwise noted


SYMBOL

PARAMETER

CONDITIONS

VSUPPLY

MIN

TYP

MAX

UNITS

VOS

Input Offset Voltage


15V

5V


0.2

0.2

0.6

0.6

mV mV



2.5V


0.3

0.8

mV

IOS

Input Offset Current


2.5V to 15V


5

15

nA

IB

Input Bias Current


2.5V to 15V


20

50

nA

en

Input Noise Voltage

f = 10kHz

2.5V to 15V

14

nV/Hz

in

Input Noise Current

f = 10kHz

2.5V to 15V

0.5

pA/Hz

RIN

Input Resistance

VCM = 12V

Differential

15V

15V

300

600

20


M M

CIN

Input Capacitance


15V

3

pF


Positive Input Voltage Range


15V

12.0

13.5


V


5V

2.5

3.5


V


2.5V

0.5

1.0


V

Negative Input Voltage Range


15V


– 13.5

– 12.0

V


5V


– 3.5

– 2.5

V


2.5V


– 1.0

– 0.5

V

CMRR

Common Mode Rejection Ratio

VCM = 12V VCM = 2.5V VCM = 0.5V

15V

5V

2.5V

80

78

68

94

86

77


dB dB dB

PSRR

Power Supply Rejection Ratio

VS = 2.5V to 15V


90

106


dB


ELECTRICAL CHARACTERISTICS TA = 25C, VCM = 0V unless otherwise noted


SYMBOL

PARAMETER

CONDITIONS

VSUPPLY

MIN

TYP

MAX

UNITS

AVOL

Large-Signal Voltage Gain

VOUT = 12V, RL = 5k VOUT = 10V, RL = 2k VOUT = 10V, RL = 1k VOUT = 2.5V, RL = 5k VOUT = 2 .5V, RL = 2k VOUT = 2.5V, RL = 1k

VOUT = 1V, RL = 5k

15V

15V

15V

5V

5V

5V

2.5V

40

30

20

30

25

15

20

80

60

40

60

50

30

40


V/mV V/mV V/mV V/mV V/mV V/mV V/mV

VOUT

Output Swing

RL = 5k, VIN = 10mV RL = 2k, VIN = 10mV RL = 1k, VIN = 10mV RL = 1k, VIN = 10mV RL= 500, VIN = 10mV

RL = 5k, VIN = 10mV

15V

15V

15V

5V

5V

2.5V

13.5

13.4

13.0

3.5

3.4

1.3

14.0

13.8

13.4

4.0

3.8

1.7


V

V

V

V

V

V

IOUT

Output Current

VOUT = 13V VOUT = 3.4V

15V

5V

13.0

6.8

13.4

7.6


mA mA

ISC

Short-Circuit Current

VOUT = 0V, VIN = 3V

15V

30

45


mA

SR

Slew Rate

AV = – 1, RL = 5k (Note 4)

15V

5V

120

30

200

50


V/s V/s


Full-Power Bandwidth

10V Peak (Note 5) 3V Peak (Note 5)

15V

5V

3.2

2.6

MHz MHz

GBW

Gain Bandwidth

f = 200kHz, RL = 10k

15V

5V

2.5V

2.0

1.8

3.0

2.7

2.5


MHz MHz MHz

tr, tf

Rise Time, Fall Time

AV = 1, 10% to 90%, 0.1V

15V

5V

46

53

ns ns


Overshoot

AV = 1, 0.1V

15V

5V

13

16

%

%


Propagation Delay

50% VIN to 50% VOUT, 0.1V

15V

5V

41

52

ns ns

ts

Settling Time

10V Step, 0.1%, AV = – 1

10V Step, 0.01%, AV = – 1

5V Step, 0.1%, AV = – 1

5V Step, 0.01%, AV = – 1

15V

15V

5V

5V

700

1250

950

1400

ns ns ns ns

RO

Output Resistance

AV = 1, f = 20kHz

15V

1.5


Channel Separation

VOUT = 10V, RL = 2k

15V

101

120


dB

IS

Supply Current

Each Amplifier Each Amplifier

15V

5V


250

230

320

300

A

A


0C TA 70C, VCM = 0V unless otherwise noted


SYMBOL

PARAMETER

CONDITIONS

VSUPPLY

MIN TYP MAX

UNITS

VOS

Input Offset Voltage


15V

5V

2.5V

0.8

0.8

1.0

mV mV mV


Input VOS Drift

(Note 6)

2.5V to 15V

3 8

V/C

IOS

Input Offset Current


2.5V to 15V

20

nA

IB

Input Bias Current


2.5V to 15V

75

nA


ELECTRICAL CHARACTERISTICS

0C TA 70C, VCM = 0V unless otherwise noted


SYMBOL

PARAMETER

CONDITIONS

VSUPPLY

MIN

TYP MAX

UNITS

CMRR

Common Mode Rejection Ratio

VCM = 12V VCM = 2.5V VCM = 0.5V

15V

5V

2.5V

78

77

67

dB dB dB

PSRR

Power Supply Rejection Ratio

VS = 2.5V to 15V


89

dB

AVOL

Large-Signal Voltage Gain

VOUT = 12V, RL = 5k VOUT = 10V, RL = 2k

15V

15V

5V

5V

5V

2.5V

25

20

20

15

10

15

V/mV V/mV V/mV V/mV V/mV V/mV



VOUT = 2.5V, RL = 5k



VOUT = 2 .5V, RL = 2k



VOUT = 2.5V, RL = 1k



VOUT = 1V, RL = 5k

VOUT

Output Swing

RL = 5k, VIN = 10mV RL = 2k, VIN = 10mV

15V

15V

15V

5V

5V

2.5V

13.4

13.3

12.0

3.4

3.3

1.2

V

V

V

V

V

V



RL = 1k, VIN = 10mV



RL = 1k, VIN = 10mV



RL= 500, VIN = 10mV



RL = 5k, VIN = 10mV

IOUT

Output Current

VOUT = 12V VOUT = 3.3V

15V

5V

12.0

6.6

mA mA

ISC

Short-Circuit Current

VOUT = 0V, VIN = 3V

15V

24

mA

SR

Slew Rate

AV = – 1, RL = 5k (Note 4)

15V

100

V/s



5V

21

V/s

GBW

Gain Bandwidth

f = 200kHz, RL = 10k

15V

1.8

MHz



5V

1.6

MHz


Channel Separation

VOUT = 10V, RL = 2k

15V

100

dB

IS

Supply Current

Each Amplifier

15V

350

A


Each Amplifier

5V

330

A


– 40C TA 85C, VCM = 0V unless otherwise noted (Note 7)


SYMBOL

PARAMETER

CONDITIONS

VSUPPLY

MI

N TYP

MAX

UNITS

VOS

Input Offset Voltage


15V

5V

1.0

1.0

mV mV



2.5V

1.2

mV


Input VOS Drift

(Note 6)

2.5V to 15V


3

8

V/C

IOS

Input Offset Current


2.5V to 15V

50

nA

IB

Input Bias Current


2.5V to 15V

100

nA

CMRR

Common Mode Rejection Ratio

VCM = 12V

15V

5V

2.5V

76

76

66

dB dB dB



VCM = 2.5V



VCM = 0.5V

PSRR

Power Supply Rejection Ratio

VS = 2.5V to 15V


87

dB

AVOL

Large-Signal Voltage Gain

VOUT = 12V, RL = 5k VOUT = 10V, RL = 2k

15V

15V

5V

5V

5V

2.5V

20

15

15

10

8

10

V/mV V/mV V/mV V/mV V/mV V/mV



VOUT = 2.5V, RL = 5k



VOUT = 2 .5V, RL = 2k



VOUT = 2.5V, RL = 1k



VOUT = 1V, RL = 5k


ELECTRICAL CHARACTERISTICS – 40C TA 85C, VCM = 0V unless otherwise noted (Note 7)


SYMBOL

PARAMETER

CONDITIONS

VSUPPLY

MIN

TYP MAX

UNITS

VOUT

Output Swing

RL = 5k, VIN = 10mV RL = 2k, VIN = 10mV

15V

15V

15V

5V

5V

2.5V

13.3

13.2

10.0

3.3

3.2

1.1

V

V

V

V

V

V



RL = 1k, VIN = 10mV



RL = 1k, VIN = 10mV



RL= 500, VIN = 10mV



RL = 5k, VIN = 10mV

IOUT

Output Current

VOUT = 10V VOUT = 3.2V

15V

5V

10.0

6.4

mA mA

ISC

Short-Circuit Current

VOUT = 0V, VIN = 3V

15V

20

mA

SR

Slew Rate

AV = – 1, RL = 5k (Note 4)

15V

50

V/s



5V

15

V/s

GBW

Gain Bandwidth

f = 200kHz, RL = 10k

15V

1.6

MHz



5V

1.4

MHz


Channel Separation

VOUT = 10V, RL = 2k

15V

99

dB

IS

Supply Current

Each Amplifier

15V

380

A


Each Amplifier

5V

350

A


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 8V on the output with 12V

input for 15V supplies and 2V on the output with 3V input for 5V supplies.

Note 5: Full-power bandwidth is calculated from the slew rate measurement: FPBW = (Slew Rate)/2VP.

Note 6: This parameter is not 100% tested.

Note 7: The LT1352C/LT1353C are guaranteed to meet specified performance from 0C to 70C. The LT1352C/LT1353C are designed, characterized and expected to meet specified performance from

– 40C to 85C but are not tested or QA sampled at these temperatures. The LT1352I/LT1353I are guaranteed to meet specified performance from – 40C to 85C.


U W

TYPICAL PERFOR A CE CHARACTERISTICS



SUPPLY CURRENT PER AMPLIFIER (A)

350


300


250

Supply Current vs Supply Voltage and Temperature


125C


V+

– 0.5

COMMON MODE RANGE (V)

–1.0

–1.5

–2.0

Input Common Mode Range vs Supply Voltage

Input Bias Current

vs Input Common Mode Voltage

TA = 25C VS = 15V





IB =

I + + I B B

2

























30


INPUT BIAS CURRENT (nA)

20


10


–55C

25C

200


150


100

0


5 10 15 20

2.0

TA = 25C




VOS = 1mV



































1.5

1.0

0.5

V

0


5 10


15 20

0


–10


–20

–15


–10 –5 0 5


10 15

SUPPLY VOLTAGE (V)


1352/53 G01

SUPPLY VOLTAGE (V)


1352/53 G02

INPUT COMMON MODE VOLTAGE (V)

1352/53 G03


U W

TYPICAL PERFOR A CE CHARACTERISTICS


Input Bias Current vs Temperature

VS = 15V






IB =

I + + I B B

2




























































40

36

INPUT BIAS CURRENT (nA)

32

28

24

20

16

12

8

4

0


100


INPUT VOLTAGE NOISE (nV/Hz)

10


1

Input Noise Spectral Density


TA = 25C VS = 15V AV = 101 RS = 100k


en


in


10


1


0.1


110


INPUT CURRENT NOISE (pA/Hz)

OPEN-LOOP GAIN (dB)

100


90


80


70


60

Open-Loop Gain vs Resistive Load

TA = 25C


VS = 15V

VS = 5V

–50

–25 0

25 50 75

100 125

1 10 100

1k 10k

10 100 1k 10k

TEMPERATURE (C)


1352/53 G04

FREQUENCY (Hz)


Output Voltage Swing


1352/53 G05

LOAD RESISTANCE ()


Output Voltage Swing


1352/53 G06


100

Open-Loop Gain vs Temperature

vs Supply Voltage

V+


V+

– 0.5

vs Load Current

VS = 5V


85C

OUTPUT VOLTAGE SWING (V)

VS = 15V VO = 12V RL = 5k









































99 –1

OPEN-LOOP GAIN (dB)

–2

98

–3

97

3


TA = 25C VIN = 10mV


RL = 1k



RL = 2k

–1.0

OUTPUT VOLTAGE SWING (V)

–1.5

–2.0


2.0

VIN = 10mV


25C

85C

25C


–40C


25C


–40C 85C

96


95


94

–50


–25 0


25 50


75 100 125

2


1


V

0 5 10

RL = 1k RL = 2k

15 20

1.5 –40C

1.0

0.5

V

–20 –15


–10


–40C

25C

85C


– 5 0 5


10 15 20

TEMPERATURE (C)


1352/53 G07

SUPPLY VOLTAGE (V)


1352/53 G08

OUTPUT CURRENT (mA)


1352/53 G09


Output Short-Circuit Current vs Temperature

OUTPUT SHORT-CIRCUIT CURRENT (mA)

VS = 15V
















SINK






SOURCE

























60


55


50


45


40


35


30


25


10

8

6

OUTPUT STEP (V)

4

2

0

–2

–4

–6

–8

–10






















10mV



1mV






























1

0mV

1mV



VS = 15V AV = 1 OUTPUT FILTER: 1.6MHz LPF






















Settling Time vs Output Step (Noninverting)


10

8

6

OUTPUT STEP (V)

4

2

0

–2

–4

–6

–8

–10


Settling Time vs Output Step (Inverting)


































10mV



1mV
























10mV





1mV


VS = 15V AV = –1

RG = RF = 2k CF = 5pF

RL = 2k






















–50

–25 0

25 50

75 100 125

0.7 0.8

0.9 1

1.1 1.2

1.3 1.4 1.5

1.6

0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5

TEMPERATURE (C)

SETTLING TIME (s)

SETTLING TIME (s)


1352/53 G10


1352/53 G11


1352/53 G12


U W

TYPICAL PERFOR A CE CHARACTERISTICS



Gain and Phase vs Frequency

70

TA = 25C


120


1000


Output Impedance vs Frequency

TA = 25C

Frequency Response vs Capacitive Load

10

OUTPUT IMPEDANCE ()

8 TA = 25C

60 PHASE

50

VS = 15V

AV = –1

RF = RG = 5k

PHASE (DEG)

VS = 15V

100


80


100

VS = 15V

AV = 100

AV = 10 AV = 1

VS = 15V

6 AV = –1

4 RFB = RG = 5k C = 500pF

C = 100pF


C = 5000pF

C = 1000pF

GAIN (dB)

40


30


20


10


0


–10

VS = 5V VS = 5V GAIN

60


40


20


0


–20


–40

10


1


0.1


0.01

2

GAIN (dB)

0

–2

–4

–6

–8

–10


C = 10pF

1k 10k 100k 1M FREQUENCY (Hz)

10M

100M

1k 10k

100k 1M 10M FREQUENCY (Hz)

10k

100k 1M 10M FREQUENCY (Hz)


4.50

4.25

GAIN BANDWIDTH (MHz)

4.00

3.75

3.50

3.25

3.00

2.75

1352/53 G13


Gain Bandwidth and Phase Margin vs Temperature

50

VS = 15V 48

VS = 5V 46

PHASE MARGIN (DEG)

PHASE MARGIN 44

42

GAIN BANDWIDTH 40

38

VS = 15V 36


Frequency Response

vs Supply Voltage (AV = 1)

5

TA = 25C

4 AV = 1

3 RL = 5k

2

GAIN (dB)

1

0

–1

–2 15V

1352/53 G14


Frequency Response

vs Supply Voltage (AV = – 1)

5

TA = 25C

4 AV = –1

3 RF = RG = 5k

2

GAIN (dB)

1

0

–1

–2

1352/53 G15

2.50

2.25

2.00

VS = 5V

34 –3

32 –4

30 –5

5V

2.5V 3

–4

–5

15V

5V

2.5V

–50

–25 0

25 50 75

100 125

10k

100k 1M 10M

10k

100k 1M 10M

TEMPERATURE (C)


1352/53 G16

FREQUENCY (Hz)


1352/53 G17

FREQUENCY (Hz)


1352/53 G18



4.50

4.25

GAIN BANDWIDTH (MHz)

4.00

3.75

3.50

3.25

3.00

2.75

2.50

2.25

2.00

Gain Bandwidth and Phase Margin vs Supply Voltage

TA = 25C








PHASE MARGIN



















GAIN BANDWIDTH









50

48

46

44

42

40

38

36

34

32

30


120


POWER SUPPLY REJECTION RATIO (dB)

100


PHASE MARGIN (DEG)

80


60


40


20


0

Power Supply Rejection Ratio vs Frequency


COMMON MODE REJECTION RATIO (dB)





TA = 25C VS = 15V









– PSRR = +PSRR




















120


100


80


60


40


20


0

Common Mode Rejection Ratio vs Frequency


TA = 25C VS = 15V

0 5 10 15 20

10 100 1k 10k 100k

1M 10M

100

1k 10k 100k 1M

10M

SUPPLY VOLTAGE (V)

FREQUENCY (Hz)

FREQUENCY (Hz)


1352/53 G19


1352/53 G20


1352/53 G21


13523fa


U W

TYPICAL PERFOR A CE CHARACTERISTICS



200

Slew Rate vs Supply Voltage

TA = 25C


250

Slew Rate vs Temperature Slew Rate vs Input Level

TA = 25C VS = 15V AV = –1

RFB = RG = 5k

SR = (SR+ + SR)/2











































AV = –1 200


SLEW RATE (V/s)

150


100


50


0

AV = –1

RF = RG = 5k

SR = (SR+ + SR)/2


200


SLEW RATE (V/s)

150


100


50


0


VS = 15V


VS = 5V

RF = RG = RL = 5k SR = (SR+ + SR)/2

175


SLEW RATE (V/s)

150


125


100


75


50


25


0

0 5 10 15

–50 –25 0

25 50 75

100 125

0 4 8

12 16

20 24

SUPPLY VOLTAGE (V)


Total Harmonic Distortion vs Frequency

1

TOTAL HARMONIC DISTORTION (%)

TA = 25C VS = 15V


1352/53 G22

TEMPERATURE (C)


Undistorted Output Swing vs Frequency (15V)

30


1352/53 G23


AV = –1

INPUT LEVEL (VP-P)


Undistorted Output Swing vs Frequency (5V)

10

9


1352/53 G24


0.1


0.01


0.001

RL = 5k

VO = 2VP-P


AV = –1


AV = 1

25


OUTPUT VOLTAGE (VP-P)

20


15


10


5 VS = 15V RL = 5k THD = 1%

0

AV = 1

8

AV = 1

OUTPUT VOLTAGE (VP-P)

7

AV = –1

6

5

4

3

2 VS = 5V

1 RL = 5k THD = 1%

0

10 100 1k 10k 100k FREQUENCY (Hz)

1352/53 G25

10k

100k 1M

FREQUENCY (Hz)

1352/53 G26

10k

100k 1M

FREQUENCY (Hz)

1352/53 G27


–30


HARMONIC DISTORTION (dB)

–40


–50


–60


–70


–80


–90

2nd and 3rd Harmonic Distortion vs Frequency


VS = 15V AV = 1

RL = 5k

VO = 2VP-P



















3RD HARMONIC























2ND HARMONIC











– 40


–50


CROSSTALK (dB)

–60


–70


–80


–90


–100


–110


–120


TA = 25C AV = 1

RL = 1k

VIN = 15dBm







































































































Crosstalk vs Frequency


100

90

80

OVERSHOOT (%)

70

60

50

40

30

20

10

0


Capacitive Load Handling


TA = 25C VS = 15V

RL = 5k












































AV = 1














































AV = –1


















































100k


FREQUENCY (Hz)

1M


1352/53 G28

100

1k 10k 100k FREQUENCY (Hz)

1M 10M


1352/53 G29

10p

100p 1n 10n 0.1 1 CAPACITIVE LOAD (F)

1352/53 G30


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TYPICAL PERFOR A CE CHARACTERISTICS


Small-Signal Transient (AV = 1)

Small-Signal Transient (AV = – 1)

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



1352/53 G31


1352/53 G32


1352/53 G33


Large-Signal Transient (AV = 1)

Large-Signal Transient (AV = – 1)

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



1352/53 G34


1352/53 G35


1352/53 G36


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APPLICATIO S I FOR ATIO

Layout and Passive Components

The LT1352/LT1353 amplifiers are easy to use and toler- ant 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 (0.01F to 0.1F). For high drive current applications use low ESR bypass capacitors (1F to 10F tantalum).

The parallel combination of the feedback resistor and gain setting resistor on the inverting input can combine with the input capacitance to form a pole which can cause peaking or even oscillations. If feedback resistors greater than 10k are used, a parallel capacitor of value, CF >

(RG)(CIN/RF), should be used to cancel the input pole and

optimize dynamic performance. For applications where

the DC noise gain is one and a large feedback resistor is used, CF should be greater than or equal to CIN. An example would be an I-to-V converter as shown in the Typical Applications section.


Capacitive Loading

The LT1352/LT1353 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. Graphs of Frequency Response vs Capacitive Load, Capacitive Load Handling and the transient response photos clearly show these effects.

Input Considerations

Each of the LT1352/LT1353 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

13523fa


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APPLICATIO S I FOR ATIO

applications where DC accuracy must be maximized. The inputs can withstand transient differential input voltages upto 10Vwithoutdamageandneednoclampingorsource resistance for protection. Differential inputs, however, generate large supply currents (tens ofmA) as required for high slew rates. If the device is used with sustained differential inputs, the average supply current will in- crease, excessivepowerdissipation will result andthepart may be damaged. The part should not be used as a comparator, peak detector or other open-loop applica- tion with large, sustained differential inputs. Under normal, closed-loop operation, an increase of power dis- sipation is only noticeable in applications with large slewing outputs and is proportional to the magnitude of the differential input voltage and the percent of time that the inputs are apart. Measure the average supply current for the application in order to calculate the power dissipation.

Circuit Operation

The LT1352/LT1353 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 R1, a 1k resistor. The input voltage appears across the resistor generating currents which are mirrored into the high impedance node and compensation capacitor CT. Complementary followers

form an output stage which buffers the gain node from the

load. The output devices Q19 and Q22 are connected to form a composite PNP and a composite NPN.

The bandwidth is set by the input resistor and the capaci- tance on the high impedance node. The slew rate is determined by the current available to charge the high impedance node capacitance. This current is the differen- tial 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 graph Slew Rate vs Input Level illustrates this relationship. In higher gain configurations the large- signal performance and the small-signal performance both look like a single pole response.

Capacitive load compensation is provided by the RC, CC network which is bootstrapped across the output stage. When the amplifier is driving a light load the network has no effect. 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 and a zero is created by the RC combination, both of which improve the phase margin. The design ensures that even for very large load capacitances, the total phase lag can never exceed 180 degrees (zero phase margin) and the amplifier remains stable.

Power Dissipation

The LT1352/LT1353 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 of 150C under certain conditions. Maximum junction temperature TJ is calculated from the ambient temperature TA and power dissipation PD as follows:

LT1352CN8: TJ = TA + (PD)(130C/W) LT1352CS8: TJ = TA + (PD)(190C/W) LT1353CS: TJ = TA + (PD)(150C/W)

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 PD(MAX) is:

PD(MAX) = (V+ – V)(IS(MAX)) + (V+/2)2/RL or

(V+ – V)(IS(MAX)) + (V+ – VMAX)(IMAX)

Example: LT1353 in S14 at 85C, VS = 15V, RL = 500, VOUT = 5V (10mA)

PD(MAX) =(30V)(380A)+(15V– 5V)(10mA)= 111mW TJ = 85C + (4)(111mW)(150C/W) = 152C


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SI PLIFIED SCHE ATIC


V+


Q10


Q11


Q12


R2


C1 Q20


R3 Q21


Q7 R1


Q9

Q3


Q17

R6

Q19


CC


–IN


V

Q5 Q6

1k


Q8 Q4

Q2 Q1


Q14


+IN


Q13

CT


Q15

RC


Q18

R7


Q16


C2


Q23


Q22


R4


Q24 R5


OUTPUT


1352/53 SS


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TYPICAL APPLICATIO S


DAC I-to-V Converter



5k

12

DAC

INPUTS


10pF



1/2

565A TYPE


A

VOS + IOS (5k) + VOUT < 0.5LSB

VOL

LT1352

+

5k

VOUT


1352/53 TA03


400kHz Photodiode Preamp with 10kHz Highpass Loop


1N5712


10k



BPV22NF


1.5k

1/2

LT1352

+


10k


VOUT



10nF

1/2

+

LT1352


10nF


10k


1352/53 TA05



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N8 Package

8-Lead PDIP (Narrow .300 Inch)

(Reference LTC DWG # 05-08-1510)




5 .015*

77 0.381)

(10.160) MAX


8


7


6


5












1


2


3


4


.400*


.25 (6.4


.300 – .325

(7.620 – 8.255)

.045 – .065

(1.143 – 1.651)

.130 .005

(3.302 0.127)




NOTE:


.008 – .015

(0.203 – 0.381)

–.015

.325 +.035

–0.381

8.255 +0.889

INCHES


.065

(1.651) TYP


.100 (2.54)

BSC


.120

(3.048) MIN

.018 .003

(0.457 0.076)


.020

(0.508) MIN


N8 1002

  1. DIMENSIONS ARE MILLIMETERS

    *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm)


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    PACKAGE DESCRIPTIO


    S8 Package

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

    (Reference LTC DWG # 05-08-1610)



    .050 BSC


    .045 .005

    .189 – .197

    (4.801 – 5.004)

    NOTE 3

    8 7 6 5



    .245

    MIN


    .160 .005


    .228 – .244

    (5.791 – 6.197)


    .150 – .157

    (3.810 – 3.988)

    NOTE 3


    .030 .005

    TYP

    RECOMMENDED SOLDER PAD LAYOUT


    .010 – .020 45

    (0.254 – 0.508)

    .008 – .010

    (0.203 – 0.254)


    0– 8 TYP


    1 2 3 4


    .053 – .069

    (1.346 – 1.752)


    .004 – .010

    (0.101 – 0.254)



    NOTE:

    .016 – .050

    (0.406 – 1.270)

    INCHES


    .014 – .019

    (0.355 – 0.483) TYP


    .050

    (1.270) BSC

    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



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

(Reference LTC DWG # 05-08-1610)



.050 BSC


.045 .005

.337 – .344

(8.560 – 8.738)

NOTE 3

N

14 13 12 11 10 9 8



.245

MIN


1

.030 .005


.160 .005


2

3

N/2


N


.228 – .244

(5.791 – 6.197)


.150 – .157

(3.810 – 3.988)

NOTE 3

N/2

TYP

RECOMMENDED SOLDER PAD LAYOUT

1


2 3 4


5 6 7


.010 – .020 45

(0.254 – 0.508)

.008 – .010

(0.203 – 0.254)


0 – 8 TYP


.053 – .069

(1.346 – 1.752)


.004 – .010

(0.101 – 0.254)




NOTE:


.016 – .050

(0.406 – 1.270)

INCHES

.014 – .019

(0.355 – 0.483) TYP

.050

(1.270) BSC


S14 0502

  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)



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- tation that the interconnection of its circuits asdescribedherein will not infringe on existing patent rights.

13523fa

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TYPICAL APPLICATIO S


20kHz, 4th Order Butterworth Filter


VIN


4.64k


13.3k


4.64k



470pF


1/2


5.49k


11.3k


5.49k


220pF


2200pF

LT1352

+


4700pF

1/2

LT1352

+


VOUT



1352/53 TA04


RELATED PARTS


PART NUMBER

DESCRIPTION

COMMENTS

LT1351

250A, 3MHz, 200V/s Op Amp

Good DC Precision, C-Load Stable, Power Saving Shutdown

LT1354/55/56

Single/Dual/Quad 1mA, 12MHz, 400V/s Op Amp

Good DC Precision, Stable with All Capacitive Loads



16

Linear Technology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

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

13523fa LT/TP 0603 1K REV A • PRINTED IN USA


LINEAR TECHNOLOGY CORPORATION 1996

Mouser Electronics


Authorized Distributor


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LT1352IS8#PBF LT1353CS#TRPBF LT1353CS LT1353CS#PBF LT1352CS8#PBF LT1352IN8 LT1352IN8#PBF LT1352IS8 LT1353CS#TR LT1352CS8#TR LT1352IS8#TRPBF LT1352CN8 LT1352IS8#TR LT1352CS8#TRPBF LT1352CS8 LT1352CN8#PBF