Maxim > Products > Thermal Management > MAX31785

MAX31785

6-Channel Intelligent Fan Controller

Intelligent Fan Controller Cost-Effectively Improves System Energy Efficiency and Reliability

Overview

Technical Documents

Ordering Info

Status

Active: In Production.

Description

The MAX31785 is a closed-loop multichannel fan controller. Automatic closed-loop fan control saves system power by operating the fans at the lowest possible speeds. Added benefits of slower fan speeds include lower audible noise, longer fan life, and reduced system maintenance. Based on a user-programmable lookup table (LUT), the device automatically adjusts the speeds of the six independent fans based on one or more of the 11 available temperature sensors. Alternately, an external host can manually command the fan speeds and the device automatically adjusts the fan speeds. The device contains a fan-health-diagnostic function to help users predict impending fan failures. The device can also monitor up to six remote voltages.

Data Sheet

Download	Rev 2	(PDF, 1.7MB)
E-Mail

An evaluation kit is available: MAX31785K

Key Features

Six Independent Channels of Fan Control
- Supports 3-Wire and 4-Wire Fans
- Automatic Closed-Loop Fan Speed Control
- RPM- or PWM-Based Control
- Optional Manual Mode Control
- Fast and Slow PWM Frequency Options
- Staggered Fan Spin-Up Eases Power-Supply Stress
- Dual Tachometer (12-Fan Support)
- Fan-Fault Detection
- Fan-Health Status Meter
- Nonvolatile Fan Operating Run Time Meter
Supports Up to 11 Temperature Sensors
- Up to Six External Thermal Diodes with Automatic Series Resistance Cancellation
- One Internal Temperature Sensor
- Up to Four I²C Digital Temperature Sensors
- Fault Detection on All Temperature Sensors
Available 6-Channel ADC to Measure Remote Voltages
PMBus™-Compliant Command Interface
I²C/SMBus-Compatible Serial Bus with Bus Timeout Function
On-Board Nonvolatile Fault Logging and Default Configuration Setting
No External Clocking Required
+3.3V Supply Voltage

Applications/Uses

Base Stations
Industrial Controls
Network Switches/Routers
Servers
Smart Grid Network Systems

Key Specifications:

Fan Controllers

Part Number

Sensor Type

Fan Controller Functions

Fan Cntrl.

Interface

Accuracy
(±°C)

Temp. Thresh.
(°C)

Temp. Resolution
(bits)

Budgetary Price

See Notes

MAX31785

Remote

Dual Temperature Alarms

Fan Failure Detector

Remote & Local Sensor

Temperature Switch/Temperature Comparator

PWM

2-Wire/I²C/SMBus

Programmable

$3.48 @1k

See All Fan Controllers (19)

Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

Diagram

Typical Operating Circuit

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Information Index

Overview		Technical Documents		Ordering Info		Related Products
Description Key Features Applications/Uses Key Specifications Diagram Notes and Comments		Data Sheet Application Notes Evaluation Kits Product Guides Reliability Reports Software/Models		Price and Availability Samples Buy Online Package Information Lead-Free Information		Similar Products by Function Similar Products by Application Evaluation Kits Products with Similar Part Numbers Products Used With This

Document Ref.: 19-5703 Rev 2; 2012-01-18
This page last modified: 2012-01-18