EMC1187 Datasheet, PDF (1/47 Pages) SMSC Corporation – Triple Channel 1°C Temperature Sensor with Hardware

EMC1187
Triple Channel 1°C Temperature Sensor with Hardware
Thermal Shutdown and 1.8V SMBus Communications
PRODUCT FEATURES
General Description
The EMC1187 is a high accuracy, low cost, 1.8V System
Management Bus (SMBus) compatible temperature sensor.
Advanced features such as Resistance Error Correction (REC),
Beta Compensation (to support CPU diodes requiring the
BJT/transistor model including 65nm and lower geometry
processors) and automatic diode type detection combine to
provide a robust solution for complex environmental monitoring
applications. The ability to communicate at 1.8V SMBus levels
provides compatible I/O for the advanced processors found in
today’s tablet and smartphone applications.
The EMC1187 monitors three temperature channels (two
external and one internal), providing ±1°C accuracy for both
external and internal diode temperatures.
Additionally, the EMC1187provides 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.
REC automatically eliminates the temperature error caused by
series resistance allowing greater flexibility in routing thermal
diodes. Frequency hopping* and analog filters ensure remote
diode traces can be as far as eight (8) inches without degrading
the signal. 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
— Supports 65nm and lower geometry CPU thermal
diodes
 Pin and register compatible with EMC1423
 Automatically determines external diode type and
optimal settings
 Resistance Error Correction
 Frequency hops the remote sample frequency to reject
DC converter and other coherent noise sources*
 Consecutive Alert queue to further reduce false Alerts
 Up to 2 External Temperature Monitor
— 25°C typ, ±1°C max accuracy (20°C < T_DIODE < 110°C)
— 0.125°C resolution
— Supports up to 2.2nF diode filter capacitor
 Internal Temperature Monitor
— ±1°C accuracy
— 0.125°C resolution
 3.3V Supply Voltage
 1.8V SMBus operation
 Programmable temperature limits for ALERT (85°C
default high limit and 0°C default low limit)
 Available in small 10-pin 3mm x 3mm DFN RoHS
compliant package
Switching
Current
VDD
EMC1187
DP1
DN1
DP2
DN2
Analog
Mux
ΔΣ ADC
External
Temperature
Register(s)
Internal
Temperature
Register
Internal
Temp Diode
Status Registers
GND
* Technology covered under the US patent 7,193,543.
SMSC EMC1187
SYS_SHDN Limit
Conversion Rate Register
Low Limit Registers
High Limit Registers
CPU
Thermal
diode
Configuration Register
Interupt Masking
SMCLK
SMDATA
ALERT
SYS_SHDN
DATASHEET
VDD = 3.3V 1.8V – 3.3V
VDD
EMC1187
DP1
DN1
Internal
Diode
SMCLK
SMDATA
ALERT
Host
SMBus
Interface
DP2
DN2
SYS_SHDN
Power
Control
Revision 1.0 (07-11-13)