Rainbow Electronics MAX6641 - Manual

General Description
The MAX6641 temperature sensor and fan controller
accurately measures the temperature of its own die and
the temperature of a remote pn junction. The device
reports temperature values in digital form using a 2-wire
serial interface. The remote pn junction is typically the
emitter-base junction of a common-collector pnp on a
CPU, FPGA, or ASIC.
The 2-wire serial interface accepts standard System
Management Bus (SMBus)
TM write byte, read byte,
send byte, and receive byte commands to read the
temperature data and program the alarm thresholds.
The temperature data controls a PWM output signal to
adjust the speed of a cooling fan, thereby minimizing
noise when the system is running cool, but providing
maximum cooling when power dissipation increases.
The device also features an over-temperature alarm
output to generate interrupts, throttle signals, or shut
down signals. The MAX6641 operates from supply volt-
ages in the 3.0V to 5.5V range and typically consumes
500µA of supply current.
The MAX6641 is available in a slim 10-pin µMAX ® pack-
age and is available over the automotive temperature
range (-40
°C to +125°C).
Applications
Desktop Computers
Notebook Computers
Workstations
Servers
Networking Equipment
Industrial
Features
♦ Tiny 3mm x 5mm µMAX Package
♦ Thermal Diode Input
♦ Local Temperature Sensor
♦ Open-Drain PWM Output for Fan Drive
♦ Programmable Fan Control Characteristics
♦ Automatic Fan Spin-Up Ensures Fan Start
♦ ±1°C Remote Temperature Accuracy (+60°C to
+145°C)
♦ Controlled Rate of Change Ensures Unobtrusive
Fan-Speed Adjustments
♦ Temperature Monitoring Begins at Power-On for
Fail-Safe System Protection
♦ OT Output for Throttling or Shutdown
MAX6641
SMBus-Compatible Temperature Monitor with
Automatic PWM Fan-Speed Controller
________________________________________________________________ Maxim Integrated Products 1
Ordering Information
19-3304; Rev 0; 5/04
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
PART TEMP RANGE
PIN-
PACKAGE SMBus
ADDRESS
MAX6641AUB90
-40 °C to
+125 °C
10 µMAX 1001 000x
MAX6641AUB92
-40 °C to
+125 °C
10 µMAX 1001 001x
MAX6641AUB94
-40 °C to
+125 °C
10 µMAX 1001 010x
MAX6641AUB96
-40 °C to
+125 °C
10 µMAX 1001 011x
1
2
3
4
5
10
9
8
7
6
PWMOUT
V CC
SMBDATA
SMBCLK GND
DXP
DXN
I.C.
MAX6641
µMAX
TOP VIEW
I.C. OT
Pin Configuration
µMAX is a registered trademark of Maxim Integrated Products, Inc.
SMBus is a trademark of Intel Corp.
Typical Application Circuit appears at end of data sheet.