MIC284
Micrel
MIC284
Two-Zone Thermal Supervisor
Advance Information
General Description
The MIC284 is a versatile digital thermal supervisor capable
of measuring temperature using its own internal sensor and
an inexpensive external sensor or embedded silicon diode
such as those found in the Intel Pentium III* CPU. A 2-wire
serial interface is provided to allow communication with either
I
2
C** or SMBus* masters. Features include an open-drain
over-temperature output with dedicated registers for imple-
menting fan control or over-temperature shutdown circuits.
Interrupt status and mask bits are provided for reduced
software overhead. The open-drain interrupt output pin can
be used as either an overtemperature alarm or a thermostatic
control signal. A programmable address pin permits two
devices to share the bus. (Alternate base addresses avail-
able-contact Micrel.) Superior performance, low power and
small size makes the MIC284 an excellent choice for the most
demanding thermal management applications.
*SMBus and Pentium III are trademarks of Intel Corporation.
**I
2
C
is a trademark of Philips Electronics, N.V.
Features
• Optimized for CPU Thermal Supervision in Computing
Applications
• Measures Local and Remote Temperature
• Sigma-Delta ADC for 8-Bit Temperature Results
• 2-Wire SMBus-compatible Interface
• Programmable Thermostat Settings for both Internal and
External Zones
• Open-Drain Interrupt Output Pin
• Open-Drain Over Temperature Output Pin for Fan
Control or Hardware Shutdown
• Interrupt Mask and Status Bits
• Low Power Shutdown Mode
• Failsafe response to diode faults
• 2.7V to 5.5V Power Supply Range
• 8-Lead SOIC and MSOP Packages
Applications
•
•
•
•
•
Desktop, Server and Notebook Computers
Power Supplies
Test and Measurement Equipment
Wireless Systems
Networking/Datacom Hardware
Junction Temp. Range
–55°C to +125°C
–55°C to +125°C
–55°C to +125°C
–55°C to +125°C
–55°C to +125°C
–55°C to +125°C
–55°C to +125°C
–55°C to +125°C
Package
8-Lead SOP
8-Lead SOP
8-Lead SOP
8-Lead SOP
8-Lead MSOP
8-Lead MSOP
8-Lead MSOP
8-Lead MSOP
Contact Factory
Contact Factory
Contact Factory
Contact Factory
Contact Factory
Contact Factory
Notes
Ordering Information
Part Number
MIC284-0BM
MIC284-1BM
MIC284-2BM
MIC284-3BM
MIC284-0BMM
MIC284-1BMM
MIC284-2BMM
MIC284-3BMM
Base Address
(
*
)
100 100x
100 101x
100 110x
100 111x
100 100x
100 101x
100 110x
100 111x
* The least-significant bit of the slave address is determined by the state of the A0 pin.
Typical Application
3.3V
4
×
10k
pull-ups
FROM
SERIAL BUS
HOST
OVER-TEMP
SHUTDOWN
0.1µF
MIC284
DATA
VDD
CLK
/INT
/CRIT
T1
A0
GND
REMOTE
DIODE
2200pF
2-Channel SMBus Temperature Measurement System
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com
September 29, 2000
1
MIC284
MICREL [ MICREL SEMICONDUCTOR ]
