ADM1031ARQZ Просмотр технического описания (PDF) - ON Semiconductor

Номер в каталоге

Компоненты Описание

производитель

ADM1031ARQZ

Intelligent Temperature Monitor and Dual PWM Fan Controller

ON Semiconductor 

ADM1031

Intelligent Temperature

Monitor and Dual PWM Fan

Controller

The ADM1031 is an ACPI−compliant, three−channel digital

thermometer and under/overtemperature alarm for use in personal

computers and thermal management systems. Optimized for the

PentiumRIII, the part offers a 1°C higher accuracy, which allows

system designers to safely reduce temperature guard−banding and

increase system performance.

Two PWM fan control outputs control the speed of two cooling fans

by varying output duty cycle. Duty cycle values between 33% and

100% allow smooth control of the fans. The speed of each fan can be

monitored via TACH inputs, which can be reprogrammed as analog

inputs to allow speeds for 2−wire fans to be measured via sense

resistors. The device also detects a stalled fan. A dedicated fan speed

control loop provides control without the intervention of CPU

software. It also ensures that if the CPU or system locks up, each fan

can still be controlled based on temperature measurements, and the fan

speed is adjusted to correct any changes in system temperature. Fan

speed can also be controlled using existing ACPI software.

Two inputs (4 pins) are dedicated to remote temperature−sensing

diodes with an accuracy of ±1°C, and an on−chip temperature sensor

allows ambient temperature to be monitored. The device has a

programmable INT output to indicate error conditions, and a dedicated

FAN_FAULT output to signal fan failure. The THERM pin is a

fail−safe output for overtemperature conditions that can be used to

throttle a CPU clock.

http://onsemi.com

QSOP−16

CASE 492

MARKING DIAGRAM

1

1031A

RQZ

#YYWW

xxx = Specific Device Code

#

= Pb−Free Package

YY = Date Code

WW = Work Week

PIN ASSIGNMENT

Features

• Optimized for Pentium III

♦ Reduced Guard−banding Software

♦ Automatic Fan Speed Control, Independent of CPU

Intervention After Initial Setup

• 0.125°C Resolution on External Temperature Channels

• Control Loop to Minimal Acoustic Noise and Battery

Consumption

• Remote Temperature Measurement Accurate to 1°C

Using Remote Diode (Two Channels)

• Local Sensor with 0.25°C Resolution

• Pulse Width Modulation (PWM) Fan Control for 2 Fans

• Programmable PWM Frequency and PWM Duty Cycle

• Tach Fan Speed Measurement (Two Channels)

• Analog Input to Measure Fan Speed of 2−Wire Fans

(Using Sense Resistor)

• 2−Wire System Management Bus (SMBus) with ARA

Support

PWM_OUT1 1

TACH1/AIN1 2

PWM_OUT2 3

TACH2/AIN2 4

GND 5

VCC 6

THERM 7

FAN_FAULT 8

ADM1031

16 SCL

15 SDA

14 INT(SMBALERT)

13 ADD

12 D2+

11 D2–

10 D1+

9 D1–

• Overtemperature THERM Output Pin for CPU

Throttling

• Programmable INT Output Pin

• Configurable Offsets for Temperature Channels 3.0 V

to 5.5 V Supply Range

• Shutdown Mode to Minimize Power Consumption

• Limit Comparison of All Monitored Values

• This is a Pb−Free Device

Applications

• Notebook PCs, Network Servers, and Personal Computers

• Telecommunications Equipment

ORDERING INFORMATION

See detailed ordering and shipping information in the package

dimensions section on page 29 of this data sheet.

© Semiconductor Components Industries, LLC, 2010

1

May, 2010 − Rev. 4

Publication Order Number:

ADM1031/D

Share Link: