AMC6821-Q1 Datasheet, PDF (1/54 Pages) Texas Instruments – INTELLIGENT TEMPERATURE MONITOR AND PWM FAN CONTROLLER

AMC6821-Q1
www.ti.com ...................................................................................................................................................................................................... SBAS475 – JUNE 2009
INTELLIGENT TEMPERATURE MONITOR AND PWM FAN CONTROLLER
FEATURES
1
•234 Qualified for Automotive Applications
• Remote Temperature Sensor:
±3°C Accuracy, 0.250°C Resolution
• Local Temperature Sensor:
±3°C Accuracy, 0.250°C Resolution
• PWM Controller
• PWM Frequency: 10Hz to 40kHz
• Duty Cycle: 0% to 100%, 8 Bits
• Automatic Fan Speed Control Loops
• SMBus Interface
• Power: 2.7 V to 5.5 V
• Package (Green): QSOP-16 (4mm × 5mm)
• RoHS Compliant
• Latch-Up Exceeds 100 mA
per JESD78B - Class I
DESCRIPTION
The AMC6821 is an intelligent temperature monitor and pulse-width modulation (PWM) fan controller. It is
designed for noise-sensitive or power-sensitive applications that require active system cooling. Using either a
low-frequency or a high-frequency PWM signal, this device can simultaneously drive a fan, monitor remote
sensor diode temperatures, and measure and control the fan speed so that it operates with minimal acoustic
noise at the lowest possible speed.
The AMC6821 has three fan control modes: Auto Temperature-Fan mode, Software-RPM mode, and
Software-DCY mode. Each mode controls the fan speed by changing the duty cycle of a PWM output. Auto
Temperature-Fan mode is an intelligent, closed-loop control that optimizes fan speed according to user-defined
parameters. This mode allows the AMC6821 to run as a stand-alone device without CPU intervention; the fan
can continue to be controlled (based on temperature measurements) even if the CPU or system locks up.
Software-RPM mode is a second closed-loop control. In this mode, the AMC6821 adjusts the PWM output to
maintain a consistent fan speed at a user-specified target value; that is, the device functions as a fan speed
regulator. Software-RPM mode can also be used to allow the AMC6821 to operate as a stand-alone device. The
third mode, Software-DCY, is open-loop. In Software-DCY mode, the PWM duty cycle is set directly by the value
written to the device.
The AMC6821 has a programmable SMBALERT output to indicate error conditions and a dedicated FAN-FAULT
output to indicate fan failure. The THERM pin is a fail-safe output for over-temperature conditions that can be
used to throttle a CPU clock. Additionally, the OVR pin indicates the over-temperature limit as well. All of the
alarm thresholds are set through the device registers. The AMC6821 is available in a QSOP-16 package.
T_A
–40°C to 125°C
QSOP – DBQ
ORDERING INFORMATION⁽¹⁾
PACKAGE ⁽²⁾
ORDERABLE PART NUMBER
Reel of 2500
AMC6821SQDBQRQ1
TOP-SIDE MARKING
AMC6821Q
(1) For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI
web site at www.ti.com.
(2) Package drawings, thermal data, and symbolization are available at www.ti.com/packaging.
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
Pentium M, Pentium-IV are trademarks of Intel.
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JMC is a trademark of JMC Products.
3
I2C is a trademark of Philips International, Inc.
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PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2009, Texas Instruments Incorporated