LTC6401-20

1

640120f

TYPICAL APPLICATION

FEATURES

APPLICATIONS

DESCRIPTION

1.3GHz Low Noise, Low

Distortion Differential ADC

Driver for 140MHz IF

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 LTC6401-20 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 20dB (10V/V).

The LTC6401-20 saves space and power compared to

alternative solutions using IF gain blocks and transform-

ers. The LTC6401-20 is packaged in a compact 16-lead

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

to 85°C temperature range.

■

1.3GHz –3dB Bandwidth

■

Fixed Gain of 10V/V (20dB)

■

■

■

1nV/√⎯H⎯z Internal Op Amp Noise

■

2.1nV/√⎯H⎯z Total Input Noise

■

6.2dB Noise Figure

■

Differential Inputs and Outputs

■

200Ω Input Impedance

■

2.85V to 3.5V Supply Voltage

■

50mA Supply Current (150mW)

■

1V to 1.6V Output Common Mode Voltage,

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.

29

Ω

66.5

Ω

0.1

μF

0.1

μF

640120 TA01a

LTC6401-20

ENABLE

LTC2208

10

Ω

0.1

μF + 1000pF

INPUT

0.1

μF

LTC2208 130Msps

16-Bit ADC

1.25V

3.3V

10

Ω

20dB GAIN

–IN

+IN

3.3V

+OUT

+OUTF

–OUTF

–OUT

V–

Single-Ended to Differential ADC Driver

Equivalent Output IP3 vs Frequency

FREQUENCY (MHz)

0

70

(NOTE 7)

60

50

40

30

20

10

0

100

50

150

640120 TA01b

200