LTC6401-14

1

640114f

TYPICAL APPLICATION

FEATURES

APPLICATIONS

DESCRIPTION

2GHz Low Noise, Low

Distortion Differential ADC

Driver for DC-140MHz

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 LTC6401-14 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 for transformers or AC-coupling ca-

pacitors in many applications. The gain is internally fixed

at 14dB (5V/V).

The LTC6401-14 saves space and power compared to

alternative solutions using IF gain blocks and transform-

ers. The LTC6401-14 is packaged in a compact 16-lead

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

to 85°C temperature range.

Equivalent Output IP3 vs Frequency

■

2GHz –3dB Bandwidth

■

Fixed Gain of 5V/V (14dB)

■

–91dBc IMD3 at 70MHz (Equivalent OIP3 = 49.3dBm)

■

–81dBc IMD3 at 140MHz (Equivalent OIP3 = 44.5dBm)

■

1.1nV/√⎯H⎯z Internal Op Amp Noise

■

7.3dB Noise Figure

■

Differential Inputs and Outputs

■

200Ω 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

■

■

Small 16-Lead 3mm × 3mm × 0.75mm QFN Package

■

Differential ADC Driver

■

Differential Driver/Receiver

■

Single Ended to Differential Conversion

■

IF Sampling Receivers

■

SAW Filter Interfacing

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

All other trademarks are the property of their respective owners.

R2

29

Ω

R1

68.5

Ω

C4

0.1

μF

C3

0.1

μF

640114 TA01a

LTC6401-14

LTC2208

15

Ω

C2

0.1

μF

C1

1000pF

3.3V

3.3V

15

Ω

10

Ω

10

Ω

R3

100

Ω

C5

0.1

μF

1.25V

33pF

COILCRAFT

0603CS

33pF

L1

24nH

33pF

–IN

+IN

+OUT

–OUT

V–

LTC2208

130Msps

16-Bit ADC

0

100 120 140 160 180

20 40 60 80

200

FREQUENCY (MHz)

60

50

40

20

10

30

0

640114 TA01b

(NOTE 7)