General Description

The MAX1270/MAX1271 are multirange, 12-bit data-

acquisition systems (DAS) that require only a single

+5V supply for operation, yet accept signals at their

analog inputs that can span above the power-supply

rail and below ground. These systems provide eight

analog input channels that are independently software

programmable for a variety of ranges: ±10V, ±5V, 0 to

ing increases the effective dynamic range to 14 bits and

provides the flexibility to interface 4–20mA, ±12V, and

±15V powered sensors directly to a single +5V system.

In addition, these converters are fault protected to

±16.5V; a fault condition on any channel will not affect

the conversion result of the selected channel. Other fea-

tures include a 5MHz bandwidth track/hold, software-

selectable internal/external clock, 110ksps throughput

rate, and internal 4.096V or external reference operation.

The MAX1270/MAX1271 serial interface directly

connects to SPI™/QSPI™ and MICROWIRE™ devices

without external logic.

A hardware shutdown input (SHDN) and two software-

programmable power-down modes, standby (STBYPD)

or full power-down (FULLPD), are provided for low-cur-

rent shutdown between conversions. In standby mode,

the reference buffer remains active, eliminating startup

delays.

The MAX1270/MAX1271 are available in 24-pin narrow

PDIP or space-saving 28-pin SSOP packages.

Applications

Features

♦ 12-Bit Resolution, 0.5 LSB Linearity

♦ +5V Single-Supply Operation

♦ SPI/QSPI and MICROWIRE-Compatible

3-Wire Interface

♦ Four Software-Selectable Input Ranges

MAX1270: 0 to +10V, 0 to +5V, ±10V, ±5V

♦ Eight Analog Input Channels

♦ 110ksps Sampling Rate

♦ ±16.5V Overvoltage-Tolerant Input Multiplexer

♦ Internal 4.096V or External Reference

♦ Two Power-Down Modes

♦ Internal or External Clock

♦ 24-Pin Narrow PDIP or 28-Pin SSOP Packages

Multirange, +5V, 8-Channel,

Serial 12-Bit ADCs

________________________________________________________________ Maxim Integrated Products

1

CH0

CH1

CH2

CH3

CH4

CH5

CH6

CH7

DGND

4.7µF

0.1µF

0.01µF

SHDN

MAX1270

MAX1271

+5V

ANALOG

INPUTS

CS

SCLK

DIN

DOUT

SSTRB

I/O

SCK

MOSI

MISO

REF

REFADJ

AGND

MC68HCXX

Typical Operating Circuit

PART

TEMP RANGE

PIN-PACKAGE

INL

(LSB)

MAX1270ACNG

0°C to +70°C

24 Narrow PDIP

±0.5

MAX1270BCNG

0°C to +70°C

24 Narrow PDIP

±1

MAX1270ACAI

0°C to +70°C

28 SSOP

±0.5

MAX1270BCAI

0°C to +70°C

28 SSOP

±1

Ordering Information

19-4782; Rev 2; 9/04

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.

Pin Configurations appear at end of data sheet.

SPI and QSPI are trademarks of Motorola, Inc.

MICROWIRE is a trademark of National Semiconductor Corp.

Ordering Information continued at end of data sheet.

EVALUATION

KIT

AVAILABLE

Industrial Control Systems

Data-Acquisition Systems

Battery-Powered

Instruments

Automatic Testing

Robotics

Medical Instruments