Maxim > Products > Thermal Management > MAX6640

MAX6640

2-Channel Temperature Monitor with Dual Automatic PWM Fan-Speed Controller

Industry's Only Dual Temperature Sensor and Fan Controller with RPM Control

Overview

Technical Documents

Ordering Info

Status

Part Number	Status
MAX6640	Active: In Production. But some versions of the family are Not Recommended for New Designs. See Ordering Information.

Description

The MAX6640 monitors its own temperature and one external diode-connected transistor or the temperatures of two external diode-connected transistors, typically available in CPUs, FPGAs, or GPUs. The 2-wire serial interface accepts standard System Management Bus (SMBus™) write byte, read byte, send byte, and receive byte commands to read the temperature data and program the alarm thresholds. Temperature data can be read at any time over the SMBus, and three programmable alarm outputs can be used to generate interrupts, throttle signals, or overtemperature shutdown signals.

The temperature data is also used by the internal dual PWM fan-speed controller to adjust the speed of up to two cooling fans, thereby minimizing noise when the system is running cool, but providing maximum cooling when power dissipation increases. Speed control is accomplished by tachometer feedback from the fan, so that the speed of the fan is controlled, not just the PWM duty cycle. Accuracy of speed measurement is ±4%.

The MAX6640 is available in 16-pin QSOP and 16-pin TQFN 5mm x 5mm packages. It operates from 3.0V to 3.6V and consumes just 500µA of supply current.

Data Sheet

Download	Rev 2	(PDF, 220kB)
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Key Features

Two Thermal-Diode Inputs
Local Temperature Sensor
1°C Remote Temperature Accuracy (+60°C to +100°C)
Two PWM Outputs for Fan Drive (Open Drain; can be Pulled Up to +13.5V)
Programmable Fan-Control Characteristics
Automatic Fan Spin-Up Ensures Fan Start
Controlled Rate-of-Change Ensures Unobtrusive Fan-Speed Adjustments
±4% Fan-Speed Measurement Accuracy
Temperature Monitoring Begins at POR for Fail-Safe System Protection
Active-Low OT and Active-Low THERM Outputs for Throttling or Shutdown
Measures Temperatures Up to +150°C
Tiny 5mm x 5mm 16-Pin TQFN and QSOP Packages

Applications/Uses

Desktop Computers
Networking Equipment
Notebook Computers
Servers
Workstations

Diagram

Typical Operating Circuit

Application Notes

Application Note 3502		Effect of PC Board Trace Width on Remote-Diode Temperature-Sensor Accuracy
Tutorial 4679		Thermal Management Handbook

Product Guides

Thermal Management (PDF)

Reliability Reports

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Software/Models

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Ordering Information

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Tape and Reel

Sample

Part Number	Free Sample	Buy	Status	Recommended Replacement	Package: TYPE PINS FOOTPRINT DRAWING CODE/VAR *	Temp	RoHS/Lead-Free? Materials Analysis
MAX6640AEE			NRND	MAX6639	QSOP;16 pin;30.9 mm² Outline Drawing:21-0055 (PDF) Land Pattern: 90-0167 (PDF) Use pkgcode/variation: E16-1*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
MAX6640AEE+			NRND	MAX6639	QSOP;16 pin;30.9 mm² Outline Drawing:21-0055 (PDF) Land Pattern: 90-0167 (PDF) Use pkgcode/variation: E16+1*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX6640AEE+T			NRND	MAX6639	QSOP;16 pin;30.9 mm² Outline Drawing:21-0055 (PDF) Land Pattern: 90-0167 (PDF) Use pkgcode/variation: E16+1*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX6640AEE-T			NRND	MAX6639	QSOP;16 pin;30.9 mm² Outline Drawing:21-0055 (PDF) Land Pattern: 90-0167 (PDF) Use pkgcode/variation: E16-1*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
MAX6640ATE			Active		TQFN;16 pin;26 mm² Outline Drawing:21-0140 (PDF) Land Pattern: 90-0073 (PDF) Use pkgcode/variation: T1655-3*	-40°C to +125°C	RoHS/Lead-Free: No Materials Analysis
MAX6640ATE-T			Active		QFN; Land Pattern: Not Available	-40°C to +125°C	See data sheet
MAX6640YAEE+			NRND	MAX6639	QSOP;16 pin;30.9 mm² Outline Drawing:21-0055 (PDF) Land Pattern: 90-0167 (PDF) Use pkgcode/variation: E16+1*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX6640YAEE+T			NRND	MAX6639	QSOP;16 pin Land Pattern: Not Available	-40°C to +85°C	See data sheet

Notes:

Other options and links for purchasing parts are listed at: http://www.maxim-ic.com/sales.
Didn't Find What You Need? Ask our applications engineers. Expert assistance in finding parts, usually within one business day.
Part number suffixes: T or T&R = tape and reel; + = RoHS/lead-free; # = RoHS/lead-exempt; -D = drypack; -U/+U on DS parts = cut tape. More: See Full Data Sheet or Maxim Product Naming Conventions.
* Some packages have variations, listed on the drawing. "PkgCode/Variation" tells which variation the product uses. Note that "+", "#", "-" in the part number suffix describes RoHS status. Package drawings may show a different suffix character.

Similar Products by Function

MAX6641	SMBus-Compatible Temperature Monitor with Automatic PWM Fan-Speed Controller
MAX6643, MAX6644, MAX6645	Automatic PWM Fan-Speed Controllers with Overtemperature Output
MAX6678	2-Channel Temperature Monitor with Dual Automatic PWM Fan-Speed Controller and Five GPIOs

Products with Similar Part Numbers

MAX6640EVCMOD2, MAX6640EVKIT

Evaluation System/Evaluation Kit for the MAX6640

More Information

New Product Press Release

[ 2004-09-20 ]

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Document Ref.: 19-3378 Rev 2; 2008-12-17
This page last modified: 2009-11-09