EMC1422
1°C Temperature Sensor
with Hardware Thermal
Shutdown
PRODUCT FEATURES
General Description
The EMC1422 is a high accuracy, low cost, System
Management Bus (SMBus) temperature sensor.
Advanced features such as Resistance Error Correction
(REC), Beta Compensation (to support CPU diodes
requiring the BJT/transistor model including 45nm,
65nm and 90nm processors) and automatic diode type
detection combine to provide a robust solution for
complex environmental monitoring applications.
Additionally, the EMC1422 provides a hardware
programmable system shutdown feature that is
programmed at part power-up via two pull-up resistor
values and that cannot be masked or corrupted through
the SMBus.
Each device provides ±1° accuracy for external diode
temperatures and ±2°C accuracy for the internal diode
temperature. The EMC1422 monitors two temperature
channels (one external and one internal).
Resistance Error Correction automatically eliminates the
temperature error caused by series resistance allowing
greater flexibility in routing thermal diodes. Beta
Compensation eliminates temperature errors caused by
low, variable beta transistors common in today's fine
geometry processors. The automatic beta detection
feature monitors the external diode/transistor and
determines the optimum sensor settings for accurate
temperature measurements regardless of processor
technology. This frees the user from providing unique
sensor configurations for each temperature monitoring
application. These advanced features plus ±1°C
measurement accuracy provide a low-cost, highly
flexible and accurate solution for critical temperature
monitoring applications.
Datasheet
Applications
Notebook Computers
Desktop Computers
Industrial
Embedded applications
Features
Hardware Thermal Shutdown
— triggers dedicated SYS_SHDN pin
— hardware configured range 77°C to 112°C in 1°C steps
— cannot be disabled or modified by software
Support for diodes requiring the BJT/transistor model
Designed to support 45nm processors
Support for 90nm and 65nm CPU diodes
Pin compatible with ADM1032, MAX6649, and LM99
Automatically determines external diode type and
optimal settings
Resistance Error Correction
External Temperature Monitors
— ±1°C Accuracy (60°C < T
DIODE
< 100°C)
— 0.125°C Resolution
— Supports up to 2.2nF diode filter capacitor
Internal Temperature Monitor
— ±2°C accuracy
3.3V Supply Voltage
Programmable temperature limits for ALERT
Small 8-pin MSOP Lead-free RoHS Compliant
Package
EMC1422 Pin Description
VDD 1
DP 2
DN 3
SYS_SHDN 4
8
7
6
5
SMCLK
SMDATA
ALERT
GND
SMSC EMC1422
DATASHEET
Revision 1.24 (02-05-08)
SMSC [ SMSC CORPORATION ]
