General Description

The MAX11040 is a 24-bit, 4-channel, simultaneous-

sampling, sigma-delta analog-to-digital converter

(ADC). The device allows simultaneous sampling of as

many as 32 channels using a built-in cascade feature

to synchronize as many as eight devices. The serial

interface of the MAX11040 allows reading data from all

the cascaded devices using a single command. Four

modulators simultaneously convert each fully differen-

tial analog input with a programmable data output rate

ranging from 0.25ksps to 64ksps. The device achieves

106dB SNR at 16ksps and 117dB SNR at 1ksps. The

MAX11040 operates from a single +3V supply. The dif-

ferential analog input range is ±2.2V when using the

internal reference, an external reference is optional.

Each input is overvoltage protected up to ±6V without

damage. The device uses an internal crystal oscillator

or an external source for clock.

The MAX11040 is compatible with SPI™, QSPI™,

MICROWIRE™, and DSP-compatible 4-wire serial inter-

faces. An on-board interface logic allows one serial inter-

face (with a single chip select) to control up to eight

cascaded devices or 32 simultaneous sampling analog

input channels.

The MAX11040 is ideally suited for power-management

systems. Each channel includes an adjustable sam-

pling phase enabling internal compensation for phase

shift due to external dividers, transformers, or filters at

the inputs. The output data rate is adjustable with a

0.065% resolution (at 16ksps or below) to track the

varying frequency of a periodic input. A SYNC input

allows periodic alignment of the conversion timing of

multiple devices with a remote timing source.

The MAX11040 is available in a 38-pin TSSOP package

specified over the -40°C to +105°C industrial tempera-

ture range.

Applications

Power Protection Relay Equipment

Multiphase Power Systems

Industrial Data-Acquisition Systems

Medical Instrumentation

Features

♦ Four Fully Differential Simultaneously Sampled

Channels

♦ Cascadable for Up to 32 Channels of

Simultaneous Sampling

♦ 106dB SNR at 16ksps

♦ 117dB SNR at 1ksps

♦ 0.25% Error Over a 1000:1 Dynamic Range,

Processed Over 16.7ms

♦ ±2.2V Full-Scale Input Range

♦ ±6V Overvoltage Protected Inputs

♦ Internal Crystal Oscillator

♦ 2.5V, 50ppm/°C Internal Reference or External

Reference

♦ Programmable Output Data Rate

0.25ksps to 64ksps Range

0.065% Resolution

♦ Programmable Sampling Phase

0 to 333µs Delay in 1.33µs Steps

♦ SPI-/QSPI-/MICROWIRE-/DSP-Compatible 4-Wire

Serial Interface

♦ Cascadable Interface Allows Control of Up to

Eight Devices with a Single CS Signal

♦ 3.0V to 3.6V Analog Supply Voltage

♦ 38-Pin TSSOP Package

24-Bit, 4-Channel, Simultaneous-Sampling,

Cascadable, Sigma-Delta ADC

________________________________________________________________

Maxim Integrated Products

1

19-4302; Rev 0; 5/09

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com.

EVALUATION

KIT

AVAILABLE

Pin Configuration appears at end of data sheet.

Ordering Information

+

Denotes a lead(Pb)-free/RoHS-compliant package.

PART

TEMP RANGE

PIN-PACKAGE

MAX11040GUU+

-40°C to +105°C

38 TSSOP

MICROWIRE is a trademark of National Semiconductor Corp.

SPI/QSPI are trademarks of Motorola Inc.

MAX11040

24-BIT

ADC

DIGITAL

FILTER

2.5V

REFERENCE

CRYSTAL

OSCILLATOR

REFIO

AIN3+

AIN3-

REF3

24-BIT

ADC

DIGITAL

FILTER

AIN2+

AIN2-

REF2

24-BIT

ADC

DIGITAL

FILTER

AIN1+

AIN1-

REF1

24-BIT

ADC

DIGITAL

FILTER

AIN0+

AIN0-

REF0

REGISTERS AND

DIGITAL

CONTROL

SERIAL

INTERFACE

DOUT

DIN

SCLK

CS

CASCOUT

CASCIN

DRDYOUT

DRDYIN

SYNC

FAULT

OVRFLW

CLKOUT

XOUT

DGND

AGND

XIN

Functional Diagram