
  Semiconductor Components Industries, LLC, 1999
February, 2000 – Rev. 0
1
Publication Order Number:
MC1066/D
The MC1066 is a serially programmable temperature sensor
optimized for monitoring modern high performance CPUs with
on–board integrated temperature sensing diodes. Temperature data is
converted from the CPU’s diode outputs and made available as an
8–bit digital word.
Communication with the MC1066 is accomplished via the standard
System Management Bus (SMBus) commonly used in modern
computer systems. This permits reading the current internal/external
temperature, programming the threshold setpoints, and configuring
the device. Additionally, an interrupt is generated on the
ALERT/COMP pin when temperature moves outside the preset
threshold windows in either direction. A separate CRITICAL setpoint
is provided through external hardwiring for “fail safe” operation per
ACPI guidelines.
A Standby command may be sent via the SMBus or by signaling the
STBY input pin to activate the low–power Standby mode. Registers
can be accessed while in Standby mode. Address selection inputs
allow up to nine MC1066s to share the same 2–wire SMBus for
multi–zone monitoring.
All registers can be read by the host, and both polled and interrupt
driven systems are easily accommodated. Small size, low installed
cost, and ease of use make the MC1066 an ideal choice for
implementing sophisticated system management schemes, such as
ACPI.
Features
 Specifically ACPI–Compliant
 Backward Compliant to Older APM Systems
 Includes Internal 
and
 External Sensing Capability
 Outputs Temperature As 8–Bit Digital Word
 Solid State Temperature Sensing; 1
°
C Resolution
 3.0 — 5.5V Operating Range
 Independent Internal and External Threshold Set–Points With
ALERT/COMP Interrupt Output
 SMBus 2–Wire Serial Interface
 Optional CRITICAL Set–Point for Full ACPI Compliant
Implementation
 Up To Nine MC1066s May Share the Same Bus
 Low Standby Power Mode
 Low Power: 70 
μ
A (max) Operating, 10 
μ
A (max) Standby Mode
 16–Pin Plastic QSOP Package
Typical Applications
 Thermal Protection For Intel “Deschutes” Pentium
 II and Other High Performance
CPUs with Integrated On–Board Diode - No Sensor Mounting Problems!
 Accurate Temperature Sensing From Any Silicon Junction Diode
 Thermal Management in Electronic Systems: Computers, Network Equipment, Power Supplies
16–Pin QSOP
DB SUFFIX
CASE TBD
PRELIMINARY INFORMATION
http://onsemi.com
PIN CONFIGURATION
(Top View)
Device
Package
Shipping
ORDERING INFORMATION
MC1066DBR2
16–Pin QSOP
2500 Tape/Reel
MC1066
1
2
3
4
16
15
14
13
CRIT1
VDD
D+
D–
CRIT0
NC
STBY
SCL
INT_SEL
SDA
ALERT/COMP
ADD0
OS
5
6
7
8
12
11
10
9
ADD1
GND
GND