LT6600-20

1

66002f

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

s

Programmable Differential Gain via Two External

Resistors

s

Adjustable Output Common Mode Voltage

s

Operates and Specified with 3V, 5V,

±5V Supplies

s

0.5dB Ripple 4th Order Lowpass Filter with 20MHz

Cutoff

s

s

2.5MHz: 83dBc 2nd, 88dBc 3rd

20MHz: 63dBc 2nd, 64dBc 3rd

s

Fully Differential Inputs and Outputs

s

SO-8 Package

s

Compatible with Popular Differential Amplifier

Pinouts

Very Low Noise, Differential

Amplifier and 20MHz Lowpass Filter

s

High Speed ADC Antialiasing and DAC Smoothing in

Networking or Cellular Base Station Applications

s

High Speed Test and Measurement Equipment

s

Medical Imaging

s

Drop-in Replacement for Differential Amplifiers

The LT

with a 4th order 20MHz lowpass filter approximating a

Chebyshev frequency response. Most differential amplifi-

ers require many precision external components to tailor

gain and bandwidth. In contrast, with the LT6600-20, two

external resistors program differential gain, and the filter’s

20MHz cutoff frequency and passband ripple are internally

set. The LT6600-20 also provides the necessary level

shifting to set its output common mode voltage to accom-

modate the reference voltage requirements of A/Ds.

Using a proprietary internal architecture, the LT6600-20

integrates an antialiasing filter and a differential amplifier/

driver without compromising distortion or low noise

performance. At unity gain the measured in band

signal-to-noise ratio is an impressive 76dB. At higher

gains the input referred noise decreases so the part can

process smaller input differential signals without signifi-

cantly degrading the output signal-to-noise ratio.

The LT6600-20 also features low voltage operation. The

differential design provides outstanding performance for

supply.

The LT6600-20 is packaged in an SO-8 and is pin compat-

ible with stand alone differential amplifiers.

–

+

–

+

402

Ω

402

Ω

0.01

µF

0.1

µF

49.9

Ω

49.9

Ω

18pF

5V

5V

–

+

LT6600-20

A/D

LTC1748

3

4

1

7

2

8

5

6

66002 TA01a

GAIN = 402

1

µF

FREQUENCY (MHz)

0

–60

–30

–20

40

66002 TA01b

–70

–80

–120

10

20

30

–100

0

–10

–40

–50

–90

–110

INPUT 5.9MHz

An 8192 Point FFT Spectrum

DESCRIPTIO

FEATURES

APPLICATIO S

TYPICAL APPLICATIO