General Description

The MAX1108/MAX1109 low-power, 8-bit, dual-channel,

analog-to-digital converters (ADCs) feature an internal

track/hold (T/H) voltage reference, clock, and serial inter-

face. The MAX1108 is specified from +2.7V to +3.6V and

consumes only 105µA. The MAX1109 is specified from

+4.5V to +5.5V and consumes only 130µA. The analog

inputs are software configurable, allowing unipolar/bipolar

and single-ended/differential operation; battery monitor-

ing capability is also included.

The full-scale analog input range is determined by the

internal reference of +2.048V (MAX1108) or +4.096V

(MAX1109), or by an externally applied reference rang-

a software power-down mode that reduces power con-

sumption to 0.5µA when the device is not in use. The

4-wire serial interface directly connects to SPI™, QSPI™,

and MICROWIRE™ devices without external logic.

Conversions up to 50ksps are performed using either the

internal clock or an external serial-interface clock.

The MAX1108 and MAX1109 are available in a 10-pin

µMAX package with a footprint that is just 20% of an

8-pin plastic DIP.

Applications

Portable Data Logging

Hand-Held Measurement Devices

Medical Instruments

System Diagnostics

Solar-Powered Remote Systems

4–20mA-Powered Remote Systems

Receive-Signal Strength Indicators

Features

o Single Supply: +2.7V to +3.6V (MAX1108)

+4.5V to +5.5V (MAX1109)

o Low Power: 105µA at +3V and 50ksps

0.5µA in Power-Down Mode

o Software-Configurable Unipolar or Bipolar Inputs

o Internal Track/Hold

o Internal Reference: +2.048V (MAX1108)

+4.096V (MAX1109)

o SPI/QSPI/MICROWIRE-Compatible Serial Interface

o Small 10-Pin µMAX Package

Single-Supply, Low-Power,

2-Channel, Serial 8-Bit ADCs

________________________________________________________________ Maxim Integrated Products

1

1

2

3

4

5

10

9

8

7

6

SCLK

DOUT

DIN

CS

GND

CH1

CH0

MAX1108

MAX1109

µMAX

TOP VIEW

COM

REF

INPUT

SHIFT

REGISTER

CONTROL

LOGIC

T/H

SAR

INTERNAL

OSCILLATOR

OUTPUT

SHIFT

REGISTER

ANALOG

INPUT

MUX

INTERNAL

REFERENCE

DOUT

SCLK

DIN

CH0

COM

REF

CH1

CS

GND

CHARGE

REDISTRIBUTION

DAC

MAX1108

MAX1109

Functional Diagram

19-1399; Rev 1; 6/03

Pin Configuration

Ordering Information

PART

MAX1108CUB

MAX1108EUB

-40°C to +85°C

0°C to +70°C

TEMP RANGE

PIN-PACKAGE

10 µMAX

10 µMAX

MAX1109CUB

MAX1109EUB

-40°C to +85°C

0°C to +70°C

10 µMAX

10 µMAX

SPI and QSPI are trademarks of Motorola, Inc. MICROWIRE is a trademark of National Semiconductor Corp.

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.