SMSC EMC1422
DATASHEET
Revision 2.0 (08-10-12)
Datasheet
PRODUCT FEATURES
EMC1422
1°C Temperature Sensor with
Hardware Thermal Shutdown
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.
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 45nm, 65nm, and 90nm CPU thermal 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
Available in Small 8-pin MSOP Lead-free RoHS
Compliant Package
Ordering Information:
EMC1422-1-ACZL-TR FOR 8-PIN, MSOP LEAD-FREE ROHS COMPLIANT PACKAGE
Note: See
Table 1.1, "Part Selection"
for SMBus addressing options.
REEL SIZE IS 4,000 PIECES.
This product meets the halogen maximum concentration values per IEC61249-2-21
For RoHS compliance and environmental information, please visit
Please contact your SMSC sales representative for additional documentation related to this product
such as application notes, anomaly sheets, and design guidelines.
1°C Temperature Sensor with Hardware Thermal Shutdown
Datasheet
Revision 2.0 (08-10-12)
2
SMSC EMC1422
DATASHEET
Copyright © 2012 SMSC or its subsidiaries. All rights reserved.
Circuit diagrams and other information relating to SMSC products are included as a means of illustrating typical applications. Consequently, complete information sufficient for
construction purposes is not necessarily given. Although the information has been checked and is believed to be accurate, no responsibility is assumed for inaccuracies. SMSC
reserves the right to make changes to specifications and product descriptions at any time without notice. Contact your local SMSC sales office to obtain the latest specifications
before placing your product order. The provision of this information does not convey to the purchaser of the described semiconductor devices any licenses under any patent
rights or other intellectual property rights of SMSC or others. All sales are expressly conditional on your agreement to the terms and conditions of the most recently dated
version of SMSC's standard Terms of Sale Agreement dated before the date of your order (the "Terms of Sale Agreement"). The product may contain design defects or errors
known as anomalies which may cause the product's functions to deviate from published specifications. Anomaly sheets are available upon request. SMSC products are not
designed, intended, authorized or warranted for use in any life support or other application where product failure could cause or contribute to personal injury or severe property
damage. Any and all such uses without prior written approval of an Officer of SMSC and further testing and/or modification will be fully at the risk of the customer. Copies of
this document or other SMSC literature, as well as the Terms of Sale Agreement, may be obtained by visiting SMSC’s website at http://www.smsc.com. SMSC is a registered
trademark of Standard Microsystems Corporation (“SMSC”). Product names and company names are the trademarks of their respective holders.
SMSC DISCLAIMS AND EXCLUDES ANY AND ALL WARRANTIES, INCLUDING WITHOUT LIMITATION ANY AND ALL IMPLIED WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE, TITLE, AND AGAINST INFRINGEMENT AND THE LIKE, AND ANY AND ALL WARRANTIES ARISING FROM ANY COURSE
OF DEALING OR USAGE OF TRADE. IN NO EVENT SHALL SMSC BE LIABLE FOR ANY DIRECT, INCIDENTAL, INDIRECT, SPECIAL, PUNITIVE, OR CONSEQUENTIAL
DAMAGES; OR FOR LOST DATA, PROFITS, SAVINGS OR REVENUES OF ANY KIND; REGARDLESS OF THE FORM OF ACTION, WHETHER BASED ON CONTRACT;
TORT; NEGLIGENCE OF SMSC OR OTHERS; STRICT LIABILITY; BREACH OF WARRANTY; OR OTHERWISE; WHETHER OR NOT ANY REMEDY OF BUYER IS HELD
TO HAVE FAILED OF ITS ESSENTIAL PURPOSE, AND WHETHER OR NOT SMSC HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
1°C Temperature Sensor with Hardware Thermal Shutdown
Datasheet
SMSC EMC1422
3
Revision 2.0 (08-10-12)
DATASHEET
Table of Contents
Chapter 1
Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.1
Part Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Chapter 2
Pin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Chapter 3
Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.1
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.2
Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.3
SMBus Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Chapter 4
System Management Bus Interface Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.1
System Management Bus Interface Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.2
Write Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.3
Read Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.4
Send Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.5
Receive Byte. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.6
Alert Response Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.7
SMBus Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.8
SMBus Timeout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Chapter 5
Product Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.0.1
Conversion Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.0.2
Dynamic Averaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.1
SYS_SHDN Output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.2
Hardware Thermal Shutdown Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.3
ALERT Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.3.1
ALERT Pin Interrupt Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5.3.2
ALERT Pin Comparator Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5.4
ALERT and SYS_SHDN Pin Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5.5
Beta Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.6
Resistance Error Correction (REC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.7
Diode Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.8
Consecutive Alerts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.9
Digital Filter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.10
Temperature Monitors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
5.11
Temperature Measurement Results and Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
5.12
External Diode Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Chapter 6
Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
6.1
Data Read Interlock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
6.2
Temperature Data Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
6.3
Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
6.4
Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
6.5
Conversion Rate Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
6.6
Limit Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
6.7
Scratchpad Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
6.8
Therm Limit Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
6.9
External Diode Fault Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
6.10
Software Thermal Shutdown Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
6.11
Hardware Thermal Shutdown Limit Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
1°C Temperature Sensor with Hardware Thermal Shutdown
Datasheet
Revision 2.0 (08-10-12)
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SMSC EMC1422
DATASHEET
6.12
Channel Mask Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
6.13
Consecutive ALERT Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
6.14
High Limit Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
6.15
Low Limit Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
6.16
THERM Limit Status Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
6.17
Filter Control Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
6.18
Product ID Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
6.19
SMSC ID Register (FEh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
6.20
Revision Register (FFh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Chapter 7
Typical Operating Curves. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Chapter 8
Package Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
8.1
Package Markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Chapter 9
Datasheet Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
1°C Temperature Sensor with Hardware Thermal Shutdown
Datasheet
SMSC EMC1422
5
Revision 2.0 (08-10-12)
DATASHEET
List of Figures
Figure 1.1 EMC1422 Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Figure 2.1 EMC1422 Pin Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Figure 4.1 SMBus Timing Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Figure 5.1 System Diagram for EMC1422 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Figure 5.2 Block Diagram of Hardware Thermal Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Figure 5.3 Isolating ALERT and SYS_SHDN Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Figure 5.4 Temperature Filter Step Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Figure 5.5 Temperature Filter Impulse Response. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Figure 5.6 Block Diagram of Temperature Monitoring Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Figure 5.7 Diode Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Figure 8.1 8-Pin MSOP / TSSOP Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
1°C Temperature Sensor with Hardware Thermal Shutdown
Datasheet
Revision 2.0 (08-10-12)
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SMSC EMC1422
DATASHEET
List of Tables
Table 1.1 Part Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Table 2.1 EMC1422 Pin Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Table 3.1 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Table 3.2 Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Table 3.3 SMBus Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Table 4.1 Protocol Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Table 4.2 Write Byte Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Table 4.3 Read Byte Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Table 4.4 Send Byte Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Table 4.5 Receive Byte Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Table 4.6 Alert Response Address Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Table 5.1 Supply Current vs. Conversion Rate for EMC1422 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Table 5.2 SYS_SHDN Threshold Temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Table 5.3 Temperature Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Table 6.1 Register Set in Hexadecimal Order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Table 6.2 Temperature Data Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Table 6.3 Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Table 6.4 Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Table 6.5 Conversion Rate Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Table 6.6 Conversion Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Table 6.7 Temperature Limit Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Table 6.8 Scratchpad Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Table 6.9 Therm Limit Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Table 6.10 External Diode Fault Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Table 6.11 Software Thermal Shutdown Configuration Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Table 6.12 Hardware Thermal Shutdown Limit Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Table 6.13 Channel Mask Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Table 6.14 Consecutive ALERT Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Table 6.15 Consecutive Alert / THERM Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Table 6.16 High Limit Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Table 6.17 Low Limit Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Table 6.18 THERM Limit Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Table 6.19 Filter Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Table 6.20 Filter Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Table 6.21 Product ID Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Table 6.22 Manufacturer ID Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Table 6.23 Revision Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Table 9.1 Customer Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
1°C Temperature Sensor with Hardware Thermal Shutdown
Datasheet
SMSC EMC1422
7
Revision 2.0 (08-10-12)
DATASHEET
Chapter 1 Block Diagram
Figure 1.1 EMC1422 Block Diagram
1.1
Part Selection
The EMC1422 device configuration is highlighted below.
Table 1.1 Part Selection
PART
NUMBER
SMBUS
ADDRESS
FUNCTIONALITY
PRODUCT
ID
EXTERNAL
DIODES
DIODE 1
DEFAULT
CONFIGURATION
DIODE 2
DEFAULT
CONFIGURATION
OTHER
EMC1422 - 1
1001_100xb
1
Detect Diode w/ REC
enabled
N/A
Software program-
mable and mask-
able High Limit
Software program-
mable and mask-
able SYS_SHDN
Limit
Hardware set
SYS_SHDN Limit
on External Diode
1
22h
Internal
Temp Diode
Switching
Current
Analog
Mux
Internal
Temperature
Register
Di
g
ita
l M
u
x
Di
gita
l Mux
Li
m
it Compa
rat
or
Low Limit Registers
High Limit Registers
Conversion Rate Register
Interupt Masking
Status Registers
Configuration Register
SM
Bus I
n
ter
face
ALERT
SYS_SHDN
SMCLK
SMDATA
DP1
DN1
V
DD
GND
EMC1422
External
Temperature
Register(s)
ΔΣ ADC
SYS_SHDN Limit
1°C Temperature Sensor with Hardware Thermal Shutdown
Datasheet
Revision 2.0 (08-10-12)
8
SMSC EMC1422
DATASHEET
Chapter 2 Pin Description
Figure 2.1 EMC1422 Pin Diagram
APPLICATION NOTE: For the 5V tolerant pins that have a pull-up resistor (SMCLK, SMDATA, SYS_SHDN, and
ALERT), the voltage difference between VDD and the pull-up voltage must never exceed
3.6V.
The pin types are described below:
Power - these pins are used to supply either VDD or GND to the device.
AIO - Analog Input / Output.
DI - Digital Input.
OD - Open Drain Digital Output.
DIOD - Digital Input / Open Drain Output.
Table 2.1 EMC1422 Pin Description
PIN NUMBER
NAME
FUNCTION
TYPE
1
VDD
Power supply
Power
2
DP
External diode positive (anode)
connection
AIO
3
DN
External diode negative (cathode)
connection
AIO
4
SYS_SHDN
Active low System Shutdown output
signal - requires pull-up resistor
which selects the Hardware
Thermal Shutdown Limit
OD (5V)
5
GND
Ground
Power
6
ALERT
Active low digital ALERT output
signal - requires pull-up resistor
OD (5V)
7
SMDATA
SMBus Data input/output - requires
pull-up resistor
DIOD (5V)
8
SMCLK
SMBus Clock input - requires pull-
up resistor
DI (5V)
SMDATA
SMCLK
ALERT
VDD
DP1
DN1
SYS_SHDN
GND
1
2
3
4
5
8
7
6
1°C Temperature Sensor with Hardware Thermal Shutdown
Datasheet
SMSC EMC1422
9
Revision 2.0 (08-10-12)
DATASHEET
Chapter 3 Electrical Specifications
3.1
Absolute Maximum Ratings
Note: Stresses at or above those listed could cause permanent damage to the device. This is a stress
rating only and functional operation of the device at any other condition above those indicated
in the operation sections of this specification is not implied. When powering this device from
laboratory or system power supplies, it is important that the Absolute Maximum Ratings not be
exceeded or device failure can result. Some power supplies exhibit voltage spikes on their
outputs when the AC power is switched on or off. In addition, voltage transients on the AC
power line may appear on the DC output. If this possibility exists, it is suggested that a clamp
circuit be used.
Note 3.1
For the 5V tolerant pins that have a pull-up resistor (SMCLK, SMDATA, SYS_SHDN, and
ALERT), the pull-up voltage must not exceed 3.6V when the device is unpowered.
Table 3.1 Absolute Maximum Ratings
DESCRIPTION
RATING
UNIT
Supply Voltage (V
DD
)
-0.3 to 4.0
V
Voltage on 5V tolerant pins (V
5VT_pin
)
-0.3 to 5.5
V
Voltage on 5V tolerant pins (|V
5VT_pin
- V
DD
|) (see
Note 3.1
)
-0.3 to 3.6
V
Voltage on any other pin to Ground
-0.3 to V
DD
+0.3
V
Operating Temperature Range
-40 to +125
°C
Storage Temperature Range
-55 to +150
°C
Lead Temperature Range
Refer to JEDEC Spec. J-STD-020
Package Thermal Characteristics for MSOP-8
Thermal Resistance (
θ
j-a
)
140.8
°C/W
ESD Rating, All pins HBM
2000
V
1°C Temperature Sensor with Hardware Thermal Shutdown
Datasheet
Revision 2.0 (08-10-12)
10
SMSC EMC1422
DATASHEET
3.2
Electrical Specifications
Note 3.2
During the power up time, SMBus communication is permitted, however the SYS_SHDN
and ALERT pins must not be pulled low.
Table 3.2 Electrical Specifications
V
DD
= 3.0V to 3.6V, T
A
= -40°C to 125°C, all typical values at T
A
= 27°C unless otherwise noted.
CHARACTERISTIC
SYMBOL
MIN
TYP
MAX
UNITS
CONDITIONS
DC Power
Supply Voltage
V
DD
3.0
3.3
3.6
V
Supply Current
I
DD
430
850
uA
1 conversion / sec, dynamic
averaging disabled
930
1200
uA
4 conversions / sec, dynamic
averaging enabled
1120
uA
> 16 conversions / sec, dynamic
averaging enabled
Internal Temperature Monitor
Temperature Accuracy
±0.25
±1
°C
-5°C < T
A
< 100°C
±2
°C
-40°C < T
A
< 125°C
Temperature Resolution
0.125
°C
External Temperature Monitor
Temperature Accuracy
±0.25
±1
°C
+20°C < T
DIODE
< +110°C
0°C < T
A
< 100°C
±0.5
±2
°C
-40°C < T
DIODE
< 127°C
Temperature Resolution
0.125
°C
Conversion Time all
Channels
t
CONV
190
ms
EMC1422, default settings
Capacitive Filter
C
FILTER
2.2
2.5
nF
Connected across external diode
ALERT and SYS_SHDN pins
Output Low Voltage
V
OL
0.4
V
I
SINK
= 8mA
Leakage Current
I
LEAK
±5
uA
ALERT and SYS_SHDN pins
Device powered or unpowered
T
A
< 85°C
pull-up voltage < 3.6V
Power up time
15
ms
Temp selection read
Note 3.2