1

LTC1740

1740f

APPLICATIO S

DESCRIPTIO

FEATURES

BLOCK DIAGRA

14-Bit, 6Msps,

Sampling ADC

The LTC

that draws only 245mW from either a single 5V or dual

±5V supplies. This easy-to-use device includes a high

dynamic range sample-and-hold and a programmable

precision reference.

The LTC1740 has a flexible input circuit that allows differ-

ential full-scale input ranges of

±2.5V and ±1.25V with the

internal reference, or any full-scale input range up to

±2.5V with an external reference. The input common

mode voltage is arbitrary, though a 2.5V reference is

provided for single supply applications.

DC specifications include 1LSB typical INL, 0.5LSB typical

DNL and no missing codes over temperature. Outstanding

AC performance includes 79dB S/(N + D) and 91dB SFDR

at an input frequency of 2.5MHz.

The unique differential input sample-and-hold can acquire

single-ended or differential input signals up to its 80MHz

bandwidth. The 75dB common mode rejection allows

users to eliminate ground loops and common mode noise

by measuring signals differentially from the source. A

separate output logic supply allows direct connection to

3V components.

s

6Msps Sample Rate

s

s

Single 5V Supply or

±5V Supplies

s

Integral Nonlinearity Error: < 1LSB

s

Differential Nonlinearity: < 0.5LSB

s

80MHz Full-Power Bandwidth Sampling

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±2.5V and ±1.25V Bipolar Input Ranges

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2.5V Signal Ground Available

s

Out-of-Range Indicator

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True Differential Inputs with 75dB CMRR

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Power Dissipation: 245mW

s

36-Pin SSOP Package (0.209 Inch Width)

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Telecommunications

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Multiplexed Data Acquisition Systems

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High Speed Data Acquisition

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Spectral Analysis

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Imaging Systems

4096-Point FFT

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

DIGITAL CORRECTION

LOGIC

1740 TA01

MODE SELECT

PIPELINED 14-BIT ADC

S/H

1

µF

1

µF

0V OR –5V

1

µF

1000pF

+

–

1

µF

5V

3V TO 5V

1

µF

OGND

OF

D13 (MSB)

6MHz CLK

DIGITAL

OUTPUT

SENSE

+

GND

2.250V

2.5V

REFERENCE

1

19

32

33

1

µF

5V

8

9

2

3

4

5

30

29

6

GND

7

GND

10

GND

34

GND

31

11

OGND

CLK

28

35

36

12

D7

D6

18

20

D0 (LSB)

BUSY

26

27

OUTPUT

BUFFERS

FREQUENCY (MHz)

0

–120

–100

–80

–60

–40

0

0.5

1.0

1.5

2.0

1740 TA02

2.5

3.0

–20

5V SUPPLY