General Description

The MAX1421 is a +3.3V, 12-bit analog-to-digital con-

verter (ADC), featuring a fully-differential input,

pipelined, 12-stage ADC architecture with wideband

track-and-hold (T/H) and digital error correction incor-

porating a fully-differential signal path. The MAX1421 is

optimized for low-power, high-dynamic performance

applications in imaging and digital communications.

The converter operates from a single +3.3V supply,

consuming only 188mW while delivering a typical sig-

nal-to-noise ratio (SNR) of 66dB at an input frequency

of 15MHz and a sampling frequency of 40Msps. The

fully-differential input stage has a small signal -3dB

bandwidth of 400MHz and may be operated with sin-

gle-ended inputs.

An internal +2.048V precision bandgap reference sets

the full-scale range of the ADC. A flexible reference

structure accommodates an internal or externally

applied buffered or unbuffered reference for applica-

tions requiring increased accuracy or a different input

voltage range.

In addition to low operating power, the MAX1421 fea-

tures two power-down modes, a reference power-down

and a shutdown mode. In reference power-down, the

internal bandgap reference is deactivated, resulting in

a typical 2mA supply current reduction. For idle peri-

ods, a full shutdown mode is available to maximize

power savings.

The MAX1421 provides parallel, offset binary, CMOS-

compatible three-state outputs.

The MAX1421 is available in a 7mm x 7mm, 48-pin

TQFP package, and is specified over the commercial

(0°C to +70°C) and the extended industrial (-40°C to

+85°C) temperature ranges.

Pin-compatible higher- and lower-speed versions of the

MAX1421 are also available. Please refer to the

MAX1420 data sheet for a frequency of 60Msps and

the MAX1422 data sheet for a frequency of 20Msps.

________________________Applications

Medical Ultrasound Imaging

CCD Pixel Processing

Data Acquisition

Radar

IF and Baseband Digitization

Features

o Single +3.3V Power Supply

o Internal, +2.048V Precision Bandgap Reference

o Differential, Wideband Input T/H Amplifier

o Power-Down Modes

180mW (Reference Shutdown Mode)

10µW (Shutdown Mode)

o Space-Saving 48-Pin TQFP Package

12-Bit, 40Msps, +3.3V, Low-Power ADC

with Internal Reference

________________________________________________________________ Maxim Integrated Products

1

D9

D8

D7

D6

DGND

DGND

D5

D4

D3

D2

AGND

AGND

AGND

INP

INN

AGND

AGND

AGND

1

2

3

4

5

6

7

8

9

10

11

12

36

35

34

33

32

31

30

29

28

27

26

25

48-TQFP

MAX1421

Pin Configuration

19-1900; Rev 0; 5/01

Ordering Information

48 TQFP

PIN-PACKAGE

TEMP. RANGE

0°C to +70°C

MAX1421CCM

PART

Functional Diagram appears at end of data sheet.

48 TQFP

-40°C to +85°C

MAX1421ECM

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.