ADT7481

Dual Channel Temperature

Sensor and Overtemperature

Alarm

The ADT7481 is a 3−channel digital thermometer and under/ over

temperature alarm, intended for use in PCs and thermal management

systems. It can measure its own ambient temperature or the

temperature of two remote thermal diodes. These thermal diodes can

be located in a CPU or GPU, or they can be discrete diode connected

transistors. The ambient temperature, or the temperature of the remote

thermal diode, can be accurately measured to

±1°C.

The temperature

measurement range defaults to 0°C to +127°C, compatible with

ADM1032, but can be switched to a wider measurement range from

−64°C

to +191°C.

The ADT7481 communicates over a 2−wire serial interface

compatible with System Management Bus (SMBus) standards. The

SMBus address of the ADT7481 is 0x4C. An ADT7481−1 with an

SMBus address of 0x4B is also available.

An ALERT output signals when the on−chip or remote temperature

is outside the programmed limits. The THERM output is a comparator

output that allows, for example, on/off control of a cooling fan. The

ALERT output can be reconfigured as a second THERM output if

required.

Features

http://onsemi.com

1

MSOP−10

CASE 846AC

MARKING DIAGRAM

10

T0x

AYWG

G

1

T0x

A

Y

W

G

= Refer to Ordering Info Table

= Assembly Location

= Year

= Work Week

= Pb−Free Package

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1 Local and 2 Remote Temperature Sensors

0.25°C Resolution/1°C Accuracy on Remote Channels

1°C Resolution/1°C Accuracy on Local Channel

Extended, Switchable Temperature Measurement Range

0°C to 127°C (Default) or

−64°C

to +191°C

2−Wire SMBus Serial Interface with SMBus ALERT Support

Programmable Over/Undertemperature Limits

Offset Registers for System Calibration

Up to 2 Overtemperature Fail−Safe THERM Outputs

Small 10−Lead MSOP Package

240

mA

Operating Current, 5

mA

Standby Current

These are Pb−Free Devices

(Note: Microdot may be in either location)

PIN ASSIGNMENT

V

DD 1

D1+

2

D1–

3

THERM

4

GND

5

10

9

SCLK

SDATA

ALERT/THERM2

D2+

D2−

ADT7481

8

7

6

Applications

ORDERING INFORMATION

See detailed ordering and shipping information in the package

dimensions section on page 19 of this data sheet.

Desktop and Notebook Computers

Industrial Controllers

Smart Batteries

Automotive

Embedded Systems

Burn−In Applications

Instrumentation

©

Semiconductor Components Industries, LLC, 2010

June, 2010

−

Rev. 5

1

Publication Order Number:

ADT7481/D