MAX1422 Datasheet, PDF (1/15 Pages) Maxim Integrated Products – 12-Bit, 20Msps, 3.3V, Low-Power ADC with Internal Reference

19-1899; Rev 1; 5/04
12-Bit, 20Msps, 3.3V, Low-Power ADC with
Internal Reference
General Description
The MAX1422 3.3V, 12-bit analog-to-digital converter
(ADC) features a fully differential input, pipelined, 12-
stage ADC architecture with wideband track-and-hold
(T/H) and digital error correction incorporating a fully-dif-
ferential signal path. The MAX1422 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
137mW while delivering a 67dB (typ) signal-to-noise
ratio (SNR) at a 5MHz input frequency and a 20Msps
sampling frequency. The fully-differential input stage
has a small signal -3dB bandwidth of 400MHz and may
be operated with single-ended inputs.
An internal 2.048V precision bandgap reference sets
the ADCs full-scale range. A flexible reference structure
accommodates an internally or externally applied
buffered or unbuffered reference for applications
requiring increased accuracy or a different input volt-
age range.
In addition to low operating power, the MAX1422 features
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 2mA
(typ) supply current reduction. For idle periods, a full
shutdown mode is available to maximize power savings.
The MAX1422 provides parallel, offset binary, CMOS-
compatible three-state outputs.
The MAX1422 is available in a 7mm ✕ 7mm ✕ 1.4mm,
48-pin TQFP package and is specified over the com-
mercial (0°C to +70°C) and extended industrial (-40°C
to +85°C) temperature ranges.
Pin-compatible higher-speed versions of the MAX1422
are also available. Please refer to the MAX1421 data
sheet for 40Msps and the MAX1420 data sheet for
60Msps.
________________________Applications
Medical Ultrasound Imaging
CCD Pixel Processing
Data Acquisition
Radar
IF and Baseband Digitization
Features
♦ Single 3.3V Power Supply
♦ 67dB SNR at f_IN = 5MHz
♦ Internal 2.048V Precision Bandgap Reference
♦ Differential Wideband Input T/H Amplifier
♦ Power-Down Modes
130mW (Reference Shutdown Mode)
10µW (Shutdown Mode)
♦ Space-Saving 48-Pin TQFP Package
PART
MAX1422CCM
MAX1422ECM
Ordering Information
TEMP RANGE
0°C to +70°C
-40°C to +85°C
PIN-PACKAGE
48 TQFP
48 TQFP
Pin Configuration
AGND 1
AV_DD 2
AV_DD 3
AGND 4
AGND 5
INP 6
INN 7
AGND 8
AGND 9
AV_DD 10
AV_DD 11
AGND 12
MAX1422
36 D9
35 D8
34 D7
33 D6
32 DV_DD
31 DV_DD
30 DGND
29 DGND
28 D5
27 D4
26 D3
25 D2
Functional Diagram appears at end of data sheet.
TQFP
________________________________________________________________ Maxim Integrated Products 1
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.