_______________General Description

The MAX471/MAX472 are complete, bidirectional, high-

side current-sense amplifiers for portable PCs, tele-

phones, and other systems where battery/DC

power-line monitoring is critical. High-side power-line

monitoring is especially useful in battery-powered sys-

tems, since it does not interfere with the ground paths

of the battery chargers or monitors often found in

“smart” batteries.

The MAX471 has an internal 35m

Ω current-sense resis-

tor and measures battery currents up to ±3A. For appli-

cations requiring higher current or increased flexibility,

the MAX472 functions with external sense and gain-set-

ting resistors. Both devices have a current output that

can be converted to a ground-referred voltage with a

single resistor, allowing a wide range of battery volt-

ages and currents.

An open-collector SIGN output indicates current-flow

direction, so the user can monitor whether a battery is

being charged or discharged. Both devices operate

from 3V to 36V, draw less than 100µA over tempera-

ture, and include a 18µA max shutdown mode.

________________________Applications

Portable PCs:

Notebooks/Subnotebooks/Palmtops

Smart Battery Packs

Cellular Phones

Portable Phones

Portable Test/Measurement Systems

Battery-Operated Systems

Energy Management Systems

____________________________Features

o Complete High-Side Current Sensing

o Precision Internal Sense Resistor (MAX471)

o 2% Accuracy Over Temperature

o Monitors Both Charge and Discharge

o 3A Sense Capability with Internal Sense Resistor

(MAX471)

o Higher Current-Sense Capability with External

Sense Resistor (MAX472)

o 100µA Max Supply Current

o 18µA Max Shutdown Mode

o 3V to 36V Supply Operation

o 8-Pin DIP/SO Packages

______________Ordering Information

Precision, High-Side

Current-Sense Amplifiers

________________________________________________________________

Maxim Integrated Products

1

1

2

3

4

8

7

6

5

OUT

RS-

RS-

SIGN

GND

RS+

RS+

SHDN

MAX471

DIP/SO

TOP VIEW

_________________Pin Configurations

MAX471

RS+

RS+

RS-

RS-

SIGN

OUT

GND

SHDN

3V

TO

36V

100k

2000

2k

LOAD or CHARGER

LOGIC

SUPPLY

DISCHARGE/CHARGE

__________Typical Operating Circuit

19-0335; Rev 2; 12/96

PART

MAX471CPA

MAX471CSA

MAX471EPA

-40°C to +85°C

0°C to +70°C

0°C to +70°C

TEMP. RANGE

PIN-PACKAGE

8 Plastic DIP

8 SO

8 Plastic DIP

MAX471ESA

-40°C to +85°C

8 SO

MAX472CPA

0°C to +70°C

8 Plastic DIP

MAX472CSA

0°C to +70°C

8 SO

MAX472EPA

-40°C to +85°C

8 Plastic DIP

MAX472ESA

-40°C to +85°C

8 SO

MAX472 Pin Configuration continued on last page.

For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800