LTC6401IUD-26-PBF datasheet, PDF

LTC6401-26

1.6GHz Low Noise,

Low Distortion Differential

ADC Driver for DC-140MHz

FEATURES

■

DESCRIPTION

The LTC

®

6401-26 is a high-speed differential ampliﬁer

targeted at processing signals from DC to 140MHz. The

part has been speciﬁcally designed to drive 12-, 14- and

16-bit ADCs with low noise and low distortion, but can also

be used as a general-purpose broadband gain block.

The LTC6401-26 is easy to use, with minimal support

circuitry required. The output common mode voltage is

set using an external pin, independent of the inputs, which

eliminates the need of transformers or AC-coupling ca-

pacitors in many applications. The gain is internally ﬁxed

at 26dB (20V/V).

The LTC6401-26 saves space and power compared to

alternative solutions using IF gain blocks and transform-

ers. The LTC6401-26 is packaged in a compact 16-lead

3mm

×

3mm QFN package and operates over the –40°C

to 85°C temperature range.

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

All other trademarks are the property of their respective owners.

1.6GHz –3dB Bandwidth

Fixed Gain of 20V/V (26dB)

–85dBc IMD3 at 70MHz (Equivalent OIP3 = 46.5dBm)

–72dBc IMD3 at 140MHz (Equivalent OIP3 = 40dBm)

1nV/√

⎯

H

⎯

z Internal Op Amp Noise

1.5nV/√

⎯

H

⎯

z Total Input Referred Noise

6.8dB Noise Figure

Differential Inputs and Outputs

50Ω Input Impedance

2.85V to 3.5V Supply Voltage

45mA Supply Current (135mW)

1V to 1.6V Output Common Mode, Adjustable

DC- or AC-Coupled Operation

Max Differential Output Swing 4.7V

P-P

Small 16-Lead 3mm

×

3mm

×

0.75mm QFN Package

APPLICATIONS

■

Differential ADC Driver

Differential Driver/Receiver

Single Ended to Differential Conversion

IF Sampling Receivers

SAW Filter Interfacing

TYPICAL APPLICATION

Single-Ended to Differential ADC Driver at 140MHz IF

3.3V

60

50

0.1μF

1000pF

V

+

0.1μF

V

IN

150Ω

0.1μF

+IN

+OUT

L1

24nH

15Ω

VV

OCM

–OUT

COILCRAFT

0603CS

1.25V

0.1μF

100Ω

33pF

10Ω

AIN

–

15Ω

10Ω

AIN

+

V

DD

LTC2208

V

CM

33pF

OUTPUT IP3 (dBm)

40

30

20

10

0

640126 TA01a

Equivalent OIP3 vs Frequency

DIFFERENTIAL INPUT

(NOTE 7)

LTC6401-26

–IN

37.4Ω

V–

LTC2208

130Msps

16-BIT ADC

NO R

L

R

L

= 200Ω

50

100

150

FREQUENCY (MHz)

200

640126 TA01b

640126f

1

LTC6401-26

ABSOLUTE MAXIMUM RATINGS

(Note 1)

PIN CONFIGURATION

TOP VIEW

–IN

+IN

7

+OUTF

+IN

12 V–

17

11 ENABLE

10 V

+

9 V–

8

+OUT

16 15 14 13

V

+

V

+

1

UD PACKAGE

16-LEAD (3mm

×

3mm) PLASTIC QFN

T

JMAX

= 150°C,

θ

JA

= 68°C/W,

θ

JC

= 4.2°C/W

EXPOSED PAD (PIN 17) IS V

–

, MUST BE SOLDERED TO PCB

ORDER INFORMATION

LEAD FREE FINISH

LTC6401CUD-26#PBF

LTC6401IUD-26#PBF

TAPE AND REEL

PART MARKING*

PACKAGE DESCRIPTION

16-Lead (3mm

×

3mm) Plastic QFN

16-Lead (3mm

×

3mm) Plastic QFN

SPECIFIED TEMPERATURE RANGE

0°C to 70°C

–40°C to 85°C

LTC6401CUD-26#TRPBF LCDG

LTC6401IUD-26#TRPBF LCDG

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

Consult LTC Marketing for information on non-standard lead based ﬁnish parts.

For more information on lead free part marking, go to:

http://www.linear.com/leadfree/

For more information on tape and reel speciﬁcations, go to:

http://www.linear.com/tapeandreel/

LTC6400 AND LTC6401 SELECTOR GUIDE

PART NUMBER

LTC6401-8

LTC6401-20

LTC6401-26

LTC6400-20

LTC6400-26

GAIN

(dB)

8

20

26

20

26

GAIN

(V/V)

2.5

10

20

10

20

Please check each datasheet for complete details.

Z

IN

(DIFFERENTIAL)

(Ω)

400

200

50

200

50

I

CC

(mA)

45

50

45

90

85

In addition to the LTC6401 family of ampliﬁers, a lower distortion LTC6400 family is available. The LTC6400 is pin compatible to the LTC6401, and has the

same low noise performance. The low distortion of the LTC6400 comes at the expense of higher power consumption. Please refer to the separate LTC6400

data sheets for complete details. Other gain versions from 8dB to 14dB will follow.

–OUTF

–OUT

Supply Voltage (V

+

– V

–

)..........................................3.6V

Input Current (Note 2)..........................................±10mA

Operating Temperature Range

(Note 3) ............................................... –40°C to 85°C

Speciﬁed Temperature Range

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

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

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

V

OCM

2

3

V– 4

5

6

640126f

2

LTC6401-26

DC ELECTRICAL CHARACTERISTICS

+

The

●

–

denotes the speciﬁcations which apply over the full operating

temperature range, otherwise speciﬁcations are at T

A

= 25°C. V = 3V, V = 0V, +IN = –IN = V

OCM

= 1.25V,

⎯

E

⎯

N

⎯

A

⎯

B

⎯

L

⎯

E = 0V, No R

L

unless

otherwise noted.

PARAMETER

Gain

Gain Temperature Drift

Output Swing Low

Output Swing High

Maximum Differential Output Swing

Output Current Drive

Input Offset Voltage

Input Offset Voltage Drift

Input Common Mode Voltage Range, MIN

Input Common Mode Voltage Range, MAX

Input Resistance (+IN, –IN)

Input Capacitance (+IN, –IN)

Output Resistance (+OUT, –OUT)

Filtered Output Resistance (+OUTF, –OUTF)

Filtered Output Capacitance (+OUTF, –OUTF)

Common Mode Rejection Ratio

Differential

Differential, Includes Parasitic

Differential

Differential, Includes Parasitic

Input Common Mode Voltage

1.1V to1.4V

V

OCM

= 1V to 1.6V

●

SYMBOL

G

DIFF

TC

GAIN

V

SWINGMIN

V

SWINGMAX

V

OUTDIFFMAX

I

OUT

V

OS

TCV

OS

I

VRMIN

I

VRMAX

R

INDIFF

C

INDIFF

R

OUTDIFF

R

OUTFDIFF

C

OUTFDIFF

CMRR

CONDITIONS

V

IN

= ±50mV Differential

V

IN

= ±50mV Differential

Each Output, V

IN

= ±200mV Differential

Each Output, V

IN

= ±200mV Differential

1dB Compressed

Each Output, V

IN

= ±200mV,

V

OUT

> 2V

P-P

Differential

●

MIN

25

TYP

26

0.003

0.09

MAX

27

0.15

UNITS

dB

dB/°C

V

P-P

mA

Input/Output Characteristic (+IN, –IN, +OUT, –OUT, +OUTF, –OUTF)

2.3

4.3

10

–2.5

2.43

4.7

2.5

1

mV

μV/°C

V

Ω

pF

Ω

pF

dB

1.6

42.5

18

85

50

1

25

100

2.7

75

32

115

57.5

Output Common Mode Control

G

CM

V

OCMMIN

V

OCMMAX

V

OSCM

TCV

OSCM

IV

OCM

⎯

E

⎯

N

⎯

A

⎯

B

⎯

L

⎯

E Pin

V

IL

V

IH

I

IL

I

IH

Power Supply

V

S

I

S

I

SHDN

PSRR

Operating Supply Range

Supply Current

Shutdown Supply Current

Power Supply Rejection Ratio (Differential

Outputs)

⎯

EN

⎯

A

⎯

B

⎯

L

⎯

E = 0V, Both Inputs and

⎯

Outputs Floating

⎯

E

⎯

N

⎯

A

⎯

B

⎯

L

⎯

E = 3V, Both Inputs and

Outputs Floating

2.85V to 3.5V

●

Common Mode Gain

Output Common Mode Range, MIN

Output Common Mode Range, MAX

1

1.1

1.6

1.5

–15

3

5

15

0.8

2.4

0.5

1.4

2.85

35

3

45

0.8

60

95.5

3

3.5

60

3

15

V/V

V

mV

μV/°C

μA

V

μA

V

mA

dB

●

Common Mode Offset Voltage

Common Mode Offset Voltage Drift

V

OCM

Input Current

⎯

E

⎯

N

⎯

A

⎯

B

⎯

L

⎯

E Input Low Voltage

⎯

E

⎯

N

⎯

A

⎯

B

⎯

L

⎯

E Input High Voltage

⎯

E

⎯

N

⎯

A

⎯

B

⎯

L

⎯

E Input Low Current

⎯

E

⎯

N

⎯

A

⎯

B

⎯

L

⎯

E Input High Current

V

OCM

= 1.1V to 1.5V

●

⎯

EN

⎯

A

⎯

B

⎯

L

⎯

E = 0.8V

⎯

E

⎯

N

⎯

A

⎯

B

⎯

L

⎯

E = 2.4V

●

640126f

3

LTC6401-26

AC ELECTRICAL CHARACTERISTICS

⎯

E

⎯

N

⎯

A

⎯

B

⎯

L

⎯

E = 0V, No R

L

unless otherwise noted.

SYMBOL

–3dBBW

0.5dBBW

0.1dBBW

1/f

SR

t

S1%

t

OVDR

t

ON

t

OFF

–3dBBW

VOCM

10MHz Input Signal

HD2,10M/HD3,10M Second/Third Order Harmonic Distortion

IMD3,10M

OIP3,10M

P

1dB,10M

NF

10M

e

IN,10M

e

ON,10M

70MHz Input Signal

HD2,70M/HD3,70M Second/Third Order Harmonic Distortion

IMD3,70M

OIP3,70M

P

1dB,70M

NF

70M

e

IN,70M

e

ON,70M

Third-Order Intermodulation

(f1 = 69.5MHz f2 = 70.5MHz)

Equivalent Third-Order Output Intercept

Point (f1 = 69.5MHz f2 = 70.5MHz)

1dB Compression Point

Noise Figure

Input Referred Voltage Noise Density

Output Referred Voltage Noise Density

V

OUT

= 2V

P-P

, R

L

= 200Ω

V

OUT

= 2V

P-P

, No R

L

V

OUT

= 2V

P-P

Composite, R

L

= 200Ω

V

OUT

= 2V

P-P

Composite, No R

L

V

OUT

= 2V

P-P

Composite, No R

L

(Note 7)

R

L

= 375Ω (Notes 5, 7)

R

L

= 375Ω (Note 5)

Includes Resistors (Short Inputs)

–83/–66

–86/–81

–74

–85

46.5

17.2

6.7

1.44

28.8

dBc

dBm

dB

⎯

nV/√H

⎯

z

nV/√

⎯

H

⎯

z

Third-Order Intermodulation

(f1 = 9.5MHz f2 = 10.5MHz)

Equivalent Third-Order Output Intercept

Point (f1 = 9.5MHz f2 = 10.5MHz)

1dB Compression Point

Noise Figure

Input Referred Voltage Noise Density

Output Referred Voltage Noise Density

V

OUT

= 2V

P-P

, R

L

= 200Ω

V

OUT

= 2V

P-P

, No R

L

V

OUT

= 2V

P-P

Composite, R

L

= 200Ω

V

OUT

= 2V

P-P

Composite, No R

L

V

OUT

= 2V

P-P

Composite, No R

L

(Note 7)

R

L

= 375Ω (Notes 5, 7)

R

L

= 375Ω (Note 5)

Includes Resistors (Short Inputs)

–95/–81

–93/–96

–80

–97

52.5

17.3

6.8

1.5

30

dBc

dBm

dB

⎯

nV/√H

⎯

z

⎯

nV/√H

⎯

z

PARAMETER

–3dB Bandwidth

Bandwidth for 0.5dB Flatness

Bandwidth for 0.1dB Flatness

1/f Noise Corner

Slew Rate

1% Settling Time

Overdrive Recovery Time

Turn-On Time

Turn-Off Time

V

OCM

Pin Small Signal –3dB BW

Differential V

OUT

= 2V Step (Note 6)

V

OUT

= 2V

P-P

(Note 6)

V

OUT

= 1.9V

P-P

(Note 6)

+OUT, –OUT Within 10% of Final Values

I

CC

Falls to 10% of Nominal

0.1V

P-P

at V

OCM

, Measured Single-Ended

at Output (Note 6)

Speciﬁcations are at T

A

= 25°C. V

+

= 3V, V

–

= 0V, V

OCM

= 1.25V,

MIN

1.2

TYP

1.6

0.5

0.22

16

3300

3

19

93

140

14.7

MAX

UNITS

GHz

kHz

V/μs

ns

MHz

CONDITIONS

200mV

P-P,OUT

(Note 6)

200mV

P-P,OUT

(Note 6)

200mV

P-P,OUT

(Note 6)

640126f

4

LTC6401-26

AC ELECTRICAL CHARACTERISTICS

⎯

EN

⎯

A

⎯

B

⎯

L

⎯

E = 0V, No R

L

unless otherwise noted.

⎯

SYMBOL

140MHz Input Signal

HD2,140M/

HD3,140M

IMD3,140M

OIP3,140M

P

1dB,140M

NF

140M

e

N,140M

e

ON,140M

IMD

3,130M/150M

Second/Third Order Harmonic Distortion

Third-Order Intermodulation

(f1 = 139.5MHz f2 = 140.5MHz)

Equivalent Third-Order Output Intercept

Point(f1 = 139.5MHz f2 = 140.5MHz)

1dB Compression Point

Noise Figure

Input Referred Voltage Noise Density

Output Referred Voltage Noise Density

Third-Order Intermodulation

(f1 = 130MHz f2 = 150MHz)

Measure at 170MHz

V

OUT

= 2V

P-P

, R

L

= 200Ω

V

OUT

= 2V

P-P

, No R

L

V

OUT

= 2V

P-P

Composite, R

L

= 200Ω

V

OUT

= 2V

P-P

Composite, No R

L

V

OUT

= 2V

P-P

Composite, No R

L

(Note 7)

R

L

= 375Ω (Notes 5, 7)

R

L

= 375Ω (Note 5)

Includes Resistors (Short Inputs)

V

OUT

= 2V

P-P

Composite, R

L

= 375Ω

–81/–54

–85/–69

–64

–72

40

17.4

6.5

1.43

28.6

–70

–62

dBc

dBm

dB

nV/√

⎯

H

⎯

z

⎯

nV/√H

⎯

z

dBc

PARAMETER

Speciﬁcations are at T

A

= 25°C. V

+

= 3V, V

–

= 0V, V

OCM

= 1.25V,

MIN

TYP

MAX

UNITS

CONDITIONS

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:

Input pins (+IN, –IN) are protected by steering diodes to either

supply. If the inputs go beyond either supply rail, the input current should

be limited to less than 10mA.

Note 3:

The LTC6401C and LTC6401I are guaranteed functional over the

operating temperature range of –40°C to 85°C

Note 4:

The LTC6401C is guaranteed to meet speciﬁed performance from

0°C to 70°C. It 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 LTC6401I is guaranteed to meet speciﬁed performance

from –40°C to 85°C.

Note 5:

Input and output baluns used. See Test Circuit A.

Note 6:

Measured using Test Circuit B. R

L

= 87.5Ω per output.

Note 7:

Since the LTC6401-26 is a feedback ampliﬁer with low output

impedance, a resistive load is not required when driving an AD converter.

Therefore, typical output power is very small. In order to compare the

LTC6401-26 with ampliﬁers that require 50Ω output load, the output

voltage swing driving a given R

L

is converted to OIP

3

and P

1dB

as if it were

driving a 50Ω load. Using this modiﬁed convention, 2V

P-P

is by deﬁnition

equal to 10dBm, regardless of actual R

L

.

640126f

5

LTC6401IUD-26-PBF

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