ADM1021A_12 Datasheet, PDF (1/16 Pages) ON Semiconductor – Low Cost Microprocessor System Temperature Monitor Microcomputer

ADM1021A
Low Cost Microprocessor
System Temperature
Monitor Microcomputer
The ADM1021A is a two-channel digital thermometer and
under/overtemperature alarm, intended for use in personal computers
and other systems requiring thermal monitoring and management. The
device can measure the temperature of a microprocessor using
a diode-connected PNP transistor, which can be provided on-chip with
the Pentium^ III or similar processors, or can be a low cost discrete
NPN/PNP device, such as the 2N3904/2N3906. A novel measurement
technique cancels out the absolute value of the transistor’s base emitter
voltage so that no calibration is required. The second measurement
channel measures the output of an on-chip temperature sensor to
monitor the temperature of the device and its environment.
The ADM1021A communicates over a two-wire serial interface
compatible with SMBus standards. Under/overtemperature limits can
be programmed into the device over the serial bus, and an ALERT
output signals when the on-chip or remote temperature is out of range.
This output can be used as an interrupt or as an SMBus alert.
Features
 Alternative to the ADM1021
 On-chip and Remote Temperature Sensing
 No Calibration Necessary
 1C Accuracy for On-chip Sensor
 3C Accuracy for Remote Sensor
 Programmable Over/Undertemperature Limits
 Programmable Conversion rate
 2-wire SMBus Serial Interface
 Supports System Management Bus (SMBus) Alert
 200 mA Max Operating Current
 1 mA Standby Current
 3.0 V to 5.5 V Supply
 Small 16-lead QSOP Package
 This Device is Pb-Free, Halogen Free and is RoHS Compliant
Applications
 Desktop Computers
 Notebook Computers
 Smart Batteries
 Industrial Controllers
 Telecom Equipment
 Instrumentation
http://onsemi.com
QSOP 16
CASE 492
PIN ASSIGNMENT
NC 1
V_DD 2
D+ 3
D− 4
NC 5
ADD1 6
GND 7
GND 8
ADM1021A
(Top View)
16 NC
15 STBY
14 SCLK
13 NC
12 SDATA
11 ALERT
10 ADD0
9 NC
NC = No Connect
MARKING DIAGRAM
1021AA
RQZ
YYWWG
1021AARQZ = Specific Device Code
YY
= Year
WW
= Work Week
G
= Pb-Free Package
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 15 of this data sheet.
 Semiconductor Components Industries, LLC, 2012
1
July, 2012 − Rev. 9
Publication Order Number:
ADM1021A/D