EMC1402 DATA SHEET (08/10/2012) DOWNLOAD

EMC1402
1°C Temperature Sensor with
Beta Compensation
PRODUCT FEATURES
Datasheet
General Description
Applications
The EMC1402 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.
„
Each device provides ±1° accuracy for external diode
temperatures and ±2°C accuracy for the internal diode
temperature. The EMC1402 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.
SMSC EMC1402
„
„
„
Notebook Computers
Desktop Computers
Industrial
Embedded applications
Features
„
Support for diodes requiring the BJT/transistor model
„
Pin compatible with ADM1032, MAX6649, and LM99
Automatically determines external diode type and
optimal settings
Resistance Error Correction
External Temperature Monitors
— supports 45nm, 65nm, and 90nm CPU thermal diodes.
„
„
— ±1°C Accuracy (60°C < TDIODE < 100°C)
— 0.125°C Resolution
„
Internal Temperature Monitor
„
3.3V Supply Voltage
Programmable temperature limits for ALERT and
THERM
Available in Small 8-pin MSOP Lead-free RoHS
Compliant Package
— ±2°C accuracy
„
„
DATASHEET
Revision 2.0 (08-10-12)
1°C Temperature Sensor with Beta Compensation
Datasheet
Ordering Information:
EMC1402-1-ACZL-TR FOR 8-PIN, MSOP LEAD-FREE ROHS COMPLIANT PACKAGE
EMC1402-2-ACZL-TR FOR 8-PIN, MSOP LEAD-FREE ROHS COMPLIANT PACKAGE
EMC1402-3-ACZL-TR FOR 8-PIN, MSOP LEAD-FREE ROHS COMPLIANT PACKAGE
EMC1402-4-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 www.smsc.com/rohs
Please contact your SMSC sales representative for additional documentation related to this product
such as application notes, anomaly sheets, and design guidelines.
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.
Revision 2.0 (08-10-12)
2
DATASHEET
SMSC EMC1402
1°C Temperature Sensor with Beta Compensation
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
3.2
3.3
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
SMBus Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Chapter 4 System Management Bus Interface Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8
System Management Bus Interface Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Write Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Read Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Send Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Receive Byte. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Alert Response Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SMBus Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SMBus Timeout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12
12
13
13
13
13
14
14
Chapter 5 Product Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.1
5.2
5.3
5.4
5.5
5.6
5.7
5.8
5.9
5.10
5.11
5.12
Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.1.1
Conversion Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.1.2
Dynamic Averaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
THERM Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ALERT Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.3.1
ALERT Pin Interrupt Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.3.2
ALERT Pin Comparator Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Beta Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Resistance Error Correction (REC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Programmable External Diode Ideality Factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Diode Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Consecutive Alerts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Digital Filter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Temperature Monitors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Temperature Measurement Results and Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
External Diode Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15
16
16
16
17
17
17
17
17
18
18
18
18
20
20
21
Chapter 6 Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
6.1
6.2
6.3
6.4
6.5
6.6
6.7
6.8
6.9
6.10
6.11
Data Read Interlock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Temperature Data Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Conversion Rate Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Limit Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Scratchpad Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
One Shot Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Therm Limit Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Channel Mask Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Consecutive ALERT Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SMSC EMC1402
3
DATASHEET
25
25
25
26
27
28
28
29
29
29
30
Revision 2.0 (08-10-12)
1°C Temperature Sensor with Beta Compensation
Datasheet
6.12
6.13
6.14
6.15
6.16
6.17
Beta Configuration Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
External Diode Ideality Factor Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Filter Control Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Product ID Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SMSC ID Register (FEh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Revision Register (FFh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31
32
34
34
35
35
Chapter 7 Typical Operating Curves. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Chapter 8 Package Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
8.1
Package Markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Chapter 9 Datasheet Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Revision 2.0 (08-10-12)
4
DATASHEET
SMSC EMC1402
1°C Temperature Sensor with Beta Compensation
Datasheet
List of Figures
Figure 1.1
Figure 2.1
Figure 4.1
Figure 5.1
Figure 5.2
Figure 5.3
Figure 5.4
Figure 5.5
Figure 8.1
EMC1402 Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
EMC1402 Pin Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
SMBus Timing Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
System Diagram for EMC1402 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Temperature Filter Step Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Temperature Filter Impulse Response. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Block Diagram of Temperature Monitoring Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Diode Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
8-Pin MSOP / TSSOP Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
SMSC EMC1402
5
DATASHEET
Revision 2.0 (08-10-12)
1°C Temperature Sensor with Beta Compensation
Datasheet
List of Tables
Table 1.1 Part Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Table 2.1 EMC1402 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 EMC1402 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Table 5.2 Temperature Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Table 6.1 Register Set in Hexadecimal Order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Table 6.2 Temperature Data Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Table 6.3 Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Table 6.4 Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Table 6.5 Conversion Rate Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Table 6.6 Conversion Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Table 6.7 Temperature Limit Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Table 6.8 Scratchpad Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Table 6.9 One Shot Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Table 6.10 Therm Limit Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Table 6.11 Channel Mask Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Table 6.12 Consecutive ALERT Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Table 6.13 Consecutive Alert / THERM Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Table 6.14 Beta Configuration Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Table 6.15 CPU Beta Values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Table 6.16 Ideality Configuration Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Table 6.17 Ideality Factor Look-Up Table (Diode Model) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Table 6.18 Substrate Diode Ideality Factor Look-Up Table (BJT Model) . . . . . . . . . . . . . . . . . . . . . . . . . 33
Table 6.19 Filter Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Table 6.20 Filter Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Table 6.21 Product ID Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Table 6.22 Manufacturer ID Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Table 6.23 Revision Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Table 9.1 Customer Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Revision 2.0 (08-10-12)
6
DATASHEET
SMSC EMC1402
1°C Temperature Sensor with Beta Compensation
Datasheet
Chapter 1 Block Diagram
VDD
EMC1402
Conversion Rate Register
Low Limit Registers
Switching
Current
DP
Internal
Temperature
Register
DN
SMBus Interface
External
Temperature
Register(s)
ΔΣ ADC
Digital Mux
Digital Mux
Analog
Mux
Limit Comparator
High Limit Registers
THERM Limit Register
THERM Hysteresis Register
Internal
Temp Diode
SMCLK
SMDATA
Configuration Register
Status Registers
Interupt Masking
ALERT
THERM
GND
Figure 1.1 EMC1402 Block Diagram
1.1
Part Selection
The EMC1402 device configuration is highlighted below.
Table 1.1 Part Selection
FUNCTIONALITY
PART
NUMBER
SMBUS
ADDRESS
EMC1402 - 1
1001_100xb
EMC1402 - 2
1001_101xb
EMC1402 - 3
0011_000xb
EMC1402 - 4
0101_001xb
EXTERNAL
DIODES
1
SMSC EMC1402
DIODE 1
DEFAULT
CONFIGURATION
Detect Diode w/ REC
enabled
7
DATASHEET
DIODE 2
DEFAULT
CONFIGURATION
OTHER
PRODUCT
ID
Software programmable and maskable High Limits
N/A
20h
Software programmable THERM
Limits
Revision 2.0 (08-10-12)
1°C Temperature Sensor with Beta Compensation
Datasheet
Chapter 2 Pin Description
VDD
1
8
SMCLK
DP
2
7
SMDATA
DN
3
6
ALERT
THERM
4
5
GND
Figure 2.1 EMC1402 Pin Diagram
Table 2.1 EMC1402 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
THERM
Active low Critical THERM output
signal - requires pull-up resistor
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 pullup resistor
DI (5V)
APPLICATION NOTE: For the 5V tolerant pins that have a pull-up resistor (SMCLK, SMDATA, THERM, 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.
Revision 2.0 (08-10-12)
8
DATASHEET
SMSC EMC1402
1°C Temperature Sensor with Beta Compensation
Datasheet
Chapter 3 Electrical Specifications
3.1
Absolute Maximum Ratings
Table 3.1 Absolute Maximum Ratings
DESCRIPTION
RATING
UNIT
Supply Voltage (VDD)
-0.3 to 4.0
V
Voltage on 5V tolerant pins (V5VT_pin)
-0.3 to 5.5
V
Voltage on 5V tolerant pins (|V5VT_pin - VDD|) (see Note 3.1)
-0.3 to 3.6
V
-0.3 to VDD +0.3
V
Operating Temperature Range
-40 to +125
°C
Storage Temperature Range
-55 to +150
°C
Voltage on any other pin to Ground
Lead Temperature Range
Refer to JEDEC Spec. J-STD-020
Package Thermal Characteristics for MSOP-8
Thermal Resistance (θj-a)
ESD Rating, All pins HBM
140.8
°C/W
2000
V
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
SMSC EMC1402
For the 5V tolerant pins that have a pull-up resistor (SMCLK, SMDATA, THERM, and
ALERT), the pull-up voltage must not exceed 3.6V when the device is unpowered.
9
DATASHEET
Revision 2.0 (08-10-12)
1°C Temperature Sensor with Beta Compensation
Datasheet
3.2
Electrical Specifications
Table 3.2 Electrical Specifications
VDD = 3.0V to 3.6V, TA = -40°C to 125°C, all typical values at TA = 27°C unless otherwise noted.
CHARACTERISTIC
SYMBOL
MIN
TYP
MAX
UNITS
CONDITIONS
DC Power
Supply Voltage
VDD
Supply Current
IDD
3.0
3.3
3.6
V
430
850
uA
1 conversion / sec, dynamic
averaging disabled
930
1200
uA
4 conversions / sec, dynamic
averaging enabled
uA
> 16 conversions / sec, dynamic
averaging enabled
uA
Device in Standby mode, no SMBus
communications, ALERT and
THERM pins not asserted.
1120
Standby Supply Current
IDD
170
230
Internal Temperature Monitor
Temperature Accuracy
±0.25
Temperature Resolution
±1
°C
-5°C < TA < 100°C
±2
°C
-40°C < TA < 125°C
0.125
°C
External Temperature Monitor
Temperature Accuracy
Temperature Resolution
±0.25
±1
°C
+20°C < TDIODE < +110°C
0°C < TA < 100°C
±0.5
±2
°C
-40°C < TDIODE < 127°C
0.125
°C
ms
EMC1402, default settings
nF
Connected across external diode
Conversion Time all
Channels
tCONV
190
Capacitive Filter
CFILTER
2.2
2.5
ALERT and THERM pins
Output Low Voltage
VOL
Leakage Current
ILEAK
Revision 2.0 (08-10-12)
0.4
±5
10
DATASHEET
V
ISINK = 8mA
uA
ALERT and THERM pins
Device powered or unpowered
TA < 85°C
pull-up voltage < 3.6V
SMSC EMC1402
1°C Temperature Sensor with Beta Compensation
Datasheet
3.3
SMBus Electrical Characteristics
Table 3.3 SMBus Electrical Specifications
VDD = 3.0V to 3.6V, TA = -40°C to 125°C, all typical values are at TA = 27°C unless otherwise noted.
CHARACTERISTIC
SYMBOL
MIN
TYP
MAX
UNITS
CONDITIONS
SMBus Interface
Input High Voltage
VIH
2.0
VDD
V
5V Tolerant
Input Low Voltage
VIL
-0.3
0.8
V
5V Tolerant
Input High/Low Current
IIH / IIL
±5
uA
Powered or unpowered
TA < 85°C
Hysteresis
Input Capacitance
CIN
Output Low Sink Current
IOL
420
mV
5
pF
8.2
15
mA
SMDATA = 0.4V
SMBus Timing
Clock Frequency
fSMB
Spike Suppression
tSP
Bus free time Start to
Stop
tBUF
1.3
us
Hold Time: Start
tHD:STA
0.6
us
Setup Time: Start
tSU:STA
0.6
us
Setup Time: Stop
tSU:STP
0.6
us
Data Hold Time
tHD:DAT
0
us
When transmitting to the master
Data Hold Time
tHD:DAT
0.3
us
When receiving from the master
Data Setup Time
tSU:DAT
100
ns
Clock Low Period
tLOW
1.3
us
Clock High Period
tHIGH
0.6
us
Clock/Data Fall time
tFALL
300
ns
Min = 20+0.1CLOAD ns
Clock/Data Rise time
tRISE
300
ns
Min = 20+0.1CLOAD ns
Capacitive Load
CLOAD
400
pF
per bus line
SMSC EMC1402
10
400
kHz
50
ns
11
DATASHEET
Revision 2.0 (08-10-12)
1°C Temperature Sensor with Beta Compensation
Datasheet
Chapter 4 System Management Bus Interface Protocol
4.1
System Management Bus Interface Protocol
TheEMC1402 communicates with a host controller, such as an SMSC SIO, through the SMBus. The
SMBus is a two-wire serial communication protocol between a computer host and its peripheral
devices. A detailed timing diagram is shown in Figure 4.1.
For the first 15ms after power-up the device may not respond to SMBus communications.
.
TLOW
THIGH
THD:STA
TSU:STO
TRISE
SMCLK
THD:STA
TFALL
THD:DAT
TSU:STA
TSU:DAT
SMDTA
TBUF
P
S
S
S - Start Condition
P - Stop Condition P
Figure 4.1 SMBus Timing Diagram
The EMC1402 is SMBus 2.0 compatible and support Send Byte, Read Byte, Write Byte, Receive Byte,
and the Alert Response Address as valid protocols as shown below.
All of the below protocols use the convention in Table 4.1.
Table 4.1 Protocol Format
DATA SENT
TO DEVICE
# of bits sent
DATA SENT TO
THE HOST
# of bits sent
Attempting to communicate with the EMC1402 SMBus interface with an invalid slave address or invalid
protocol will result in no response from the device and will not affect its register contents. Stretching
of the SMCLK signal is supported, provided other devices on the SMBus control the timing.
4.2
Write Byte
The Write Byte is used to write one byte of data to the registers as shown below Table 4.2:
Table 4.2 Write Byte Protocol
START
SLAVE
ADDRESS
WR
ACK
REGISTER
ADDRESS
ACK
REGISTER
DATA
ACK
STOP
1 -> 0
1001_100
0
0
XXh
0
XXh
0
0 -> 1
Revision 2.0 (08-10-12)
12
DATASHEET
SMSC EMC1402
1°C Temperature Sensor with Beta Compensation
Datasheet
4.3
Read Byte
The Read Byte protocol is used to read one byte of data from the registers as shown in Table 4.3.
Table 4.3 Read Byte Protocol
START
SLAVE
ADDRESS
WR
ACK
REGISTER
ADDRESS
ACK
START
SLAVE
ADDRESS
RD
ACK
REGISTER
DATA
NACK
STOP
1 -> 0
1001_100
0
1
XXh
0
1 -> 0
1001_100
1
1
XX
1
0 -> 1
4.4
Send Byte
The Send Byte protocol is used to set the internal address register pointer to the correct address
location. No data is transferred during the Send Byte protocol as shown in Table 4.4.
Table 4.4 Send Byte Protocol
START
SLAVE
ADDRESS
WR
ACK
REGISTER
ADDRESS
ACK
STOP
1 -> 0
1001_100
0
0
XXh
0
0 -> 1
4.5
Receive Byte
The Receive Byte protocol is used to read data from a register when the internal register address
pointer is known to be at the right location (e.g. set via Send Byte). This is used for consecutive reads
of the same register as shown in Table 4.5.
Table 4.5 Receive Byte Protocol
START
SLAVE
ADDRESS
RD
ACK
REGISTER DATA
NACK
STOP
1 -> 0
1001_100
1
0
XXh
1
0 -> 1
4.6
Alert Response Address
The ALERT output can be used as a processor interrupt or as an SMBus Alert.
When it detects that the ALERT pin is asserted, the host will send the Alert Response Address (ARA)
to the general address of 0001_100xb. All devices with active interrupts will respond with their client
address as shown in Table 4.6.
Table 4.6 Alert Response Address Protocol
START
ALERT
RESPONSE
ADDRESS
RD
ACK
DEVICE
ADDRESS
NACK
STOP
1 -> 0
0001_100
1
0
1001_1000
1
0 -> 1
SMSC EMC1402
13
DATASHEET
Revision 2.0 (08-10-12)
1°C Temperature Sensor with Beta Compensation
Datasheet
The EMC1402 will respond to the ARA in the following way:
1. Send Slave Address and verify that full slave address was sent (i.e. the SMBus communication
from the device was not prematurely stopped due to a bus contention event).
2. Set the MASK bit to clear the ALERT pin.
APPLICATION NOTE: The ARA does not clear the Status Register and if the MASK bit is cleared prior to the Status
Register being cleared, the ALERT pin will be reasserted.
4.7
SMBus Address
The EMC1402 responds to hard-wired SMBus slave address as shown in Table 1.1.
Note: Other addresses are available. Contact SMSC for more information.
4.8
SMBus Timeout
The EMC1402 supports SMBus Timeout. If the clock line is held low for longer than 30ms, the device
will reset its SMBus protocol. This function can be enabled by setting the TIMEOUT bit in the
Consecutive Alert Register (see Section 6.11).
Revision 2.0 (08-10-12)
14
DATASHEET
SMSC EMC1402
1°C Temperature Sensor with Beta Compensation
Datasheet
Chapter 5 Product Description
The EMC1402 is an SMBus temperature sensor. The EMC1402 monitors one internal diode and one
externally connected temperature diode.
Thermal management is performed in cooperation with a host device. This consists of the host reading
the temperature data of both the external and internal temperature diodes of the EMC1402 and using
that data to control the speed of one or more fans.
The EMC1402 has two levels of monitoring. The first provides a maskable ALERT signal to the host
when the measured temperatures exceeds user programmable limits. This allows the EMC1402 to be
used as an independent thermal watchdog to warn the host of temperature hot spots without direct
control by the host. The second level of monitoring provides a non maskable interrupt on the THERM
pin if the measured temperatures meet or exceed a second programmable limit.
Since the EMC1402 automatically corrects for temperature errors due to series resistance in
temperature diode lines, there is greater flexibility in where external diodes are positioned and better
measurement accuracy than previously available with non-resistance error correcting devices. The
automatic beta detection feature means that there is no need to program the device according to which
type of diode is present. This also includes CPU diodes that require the transistor or BJT model for
monitoring their temperature. Therefore, the EMC1402 can power up ready to operate for any system
configuration.
Figure 5.1 shows a system level block diagram of the EMC1402.
CPU
Thermal
diode
EMC1402
Host
DP
DN
Internal
Diode
SMCLK
SMDATA
ALERT
THERM
SMBus
Interface
Power Control
Figure 5.1 System Diagram for EMC1402
5.1
Modes of Operation
The EMC1402 has two modes of operation.
„
Active (Run) - In this mode of operation, the ADC is converting on all temperature channels at the
programmed conversion rate. The temperature data is updated at the end of every conversion and
the limits are checked. In Active mode, writing to the one-shot register will do nothing.
„
Standby (Stop) - In this mode of operation, the majority of circuitry is powered down to reduce
supply current. The temperature data is not updated and the limits are not checked. In this mode
of operation, the SMBus is fully active and the part will return requested data. Writing to the oneshot register will enable the device to update all temperature channels. Once all the channels are
updated, the device will return to the Standby mode.
SMSC EMC1402
15
DATASHEET
Revision 2.0 (08-10-12)
1°C Temperature Sensor with Beta Compensation
Datasheet
5.1.1
Conversion Rates
The EMC1402 may be configured for different conversion rates based on the system requirements.
The conversion rate is configured as described in Section 6.5. The default conversion rate is 4
conversions per second. Other available conversion rates are shown in Table 6.6.
5.1.2
Dynamic Averaging
Dynamic averaging causes the EMC1402 to measure the external diode channels for an extended time
based on the selected conversion rate. This functionality can be disabled for increased power savings
at the lower conversion rates (see Section 6.4). When dynamic averaging is enabled, the device will
automatically adjust the sampling and measurement time for the external diode channels. This allows
the device to average 2x or 16x longer than the normal 11 bit operation (nominally 21ms per channel)
while still maintaining the selected conversion rate. The benefits of dynamic averaging are improved
noise rejection due to the longer integration time as well as less random variation of the temperature
measurement.
When enabled, the dynamic averaging applies when a one-shot command is issued. The device will
perform the desired averaging during the one-shot operation according to the selected conversion rate.
When enabled, the dynamic averaging will affect the average supply current based on the chosen
conversion rate as shown in Table 5.1 for the EMC1402.
Table 5.1 Supply Current vs. Conversion Rate for EMC1402
AVERAGE SUPPLY CURRENT
AVERAGING FACTOR (BASED ON
11-BIT OPERATION)
CONVERSION RATE
ENABLED
(DEFAULT)
DISABLED
ENABLED
(DEFAULT)
DISABLED
1 / 16 sec
660uA
430uA
16x
1x
1 / 8 sec
660uA
430uA
16x
1x
1 / 4 sec
660uA
430uA
16x
1x
1 / 2 sec
660uA
430uA
16x
1x
1 / sec
660uA
430uA
16x
1x
2 / sec
930uA
475uA
16x
1x
4 / sec (default)
950uA
510uA
8x
1x
8 / sec
1010uA
630uA
4x
1x
16 / sec
1020uA
775uA
2x
1x
32 / sec
1050uA
1050uA
1x
1x
64 / sec
1100uA
1100uA
0.5x
0.5x
5.2
THERM Output
The THERM output is asserted independently of the ALERT output and cannot be masked. Whenever
any of the measured temperatures exceed the user programmed THERM Limit values for the
programmed number of consecutive measurements, the THERM output is asserted. Once it has been
asserted, it will remain asserted until all measured temperatures drop below the THERM Limit minus
the THERM Hysteresis (also programmable).
Revision 2.0 (08-10-12)
16
DATASHEET
SMSC EMC1402
1°C Temperature Sensor with Beta Compensation
Datasheet
When the THERM pin is asserted, the Therm status bits will likewise be set. Reading these bits will
not clear them until the THERM pin is deasserted. Once the THERM pin is deasserted, the THERM
status bits will be automatically cleared.
5.3
ALERT Output
The ALERT pin is an open drain output and requires a pull-up resistor to VDD and has two modes of
operation: interrupt mode and comparator Mode. The mode of the ALERT output is selected via the
ALERT / COMP bit in the Configuration Register (see Section 6.4).
5.3.1
ALERT Pin Interrupt Mode
When configured to operate in interrupt mode, the ALERT pin asserts low when an out of limit
measurement (> high limit or < low limit) is detected on any diode or when a diode fault is detected.
The ALERT pin will remain asserted as long as an out-of-limit condition remains. Once the out-of-limit
condition has been removed, the ALERT pin will remain asserted until the appropriate status bits are
cleared.
The ALERT pin can be masked by setting the MASK bit. Once the ALERT pin has been masked, it
will be de-asserted and remain de-asserted until the MASK bit is cleared by the user. Any interrupt
conditions that occur while the ALERT pin is masked will update the Status Register normally.
The ALERT pin is used as an interrupt signal or as an Smbus Alert signal that allows an SMBus slave
to communicate an error condition to the master. One or more ALERT outputs can be hard-wired
together.
5.3.2
ALERT Pin Comparator Mode
When the ALERT pin is configured to operate in comparator mode it will be asserted if any of the
measured temperatures exceeds the respective high limit. The ALERT pin will remain asserted until
all temperatures drop below the corresponding high limit minus the THERM Hysteresis value.
When the ALERT pin is asserted in comparator mode, the corresponding high limit status bits will be
set. Reading these bits will not clear them until the ALERT pin is deasserted. Once the ALERT pin is
deasserted, the status bits will be automatically cleared.
The MASK bit will not block the ALERT pin in this mode, however the individual channel masks (see
Section 6.10) will prevent the respective channel from asserting the ALERT pin.
5.4
Beta Compensation
The EMC1402 is configured to monitor the temperature of basic diodes (e.g. 2N3904), or CPU thermal
diodes. It automatically detects the type of external diode (CPU diode or diode connected transistor)
and determines the optimal setting to reduce temperature errors introduced by beta
variation.Compensating for this error is also known as implementing the transistor or BJT model for
temperature measurement.
For discrete transistors configured with the collector and base shorted together, the beta is generally
sufficiently high such that the percent change in beta variation is very small. For example, a 10%
variation in beta for two forced emitter currents with a transistor whose ideal beta is 50 would contribute
approximately 0.25°C error at 100°C. However for substrate transistors where the base-emitter junction
is used for temperature measurement and the collector is tied to the substrate, the proportional beta
variation will cause large error. For example, a 10% variation in beta for two forced emitter currents
with a transistor whose ideal beta is 0.5 would contribute approximately 8.25°C error at 100°C.
5.5
Resistance Error Correction (REC)
Parasitic resistance in series with the external diodes will limit the accuracy obtainable from
temperature measurement devices. The voltage developed across this resistance by the switching
diode currents cause the temperature measurement to read higher than the true temperature.
Contributors to series resistance are PCB trace resistance, on die (i.e. on the processor) metal
SMSC EMC1402
17
DATASHEET
Revision 2.0 (08-10-12)
1°C Temperature Sensor with Beta Compensation
Datasheet
resistance, bulk resistance in the base and emitter of the temperature transistor. Typically, the error
caused by series resistance is +0.7°C per ohm. The EMC1402 automatically corrects up to 100 ohms
of series resistance.
5.6
Programmable External Diode Ideality Factor
The EMC1402 is designed for external diodes with an ideality factor of 1.008. Not all external diodes,
processor or discrete, will have this exact value. This variation of the ideality factor introduces error in
the temperature measurement which must be corrected for. This correction is typically done using
programmable offset registers. Since an ideality factor mismatch introduces an error that is a function
of temperature, this correction is only accurate within a small range of temperatures. To provide
maximum flexibility to the user, the EMC1402 provides a 6-bit register for each external diode where
the ideality factor of the diode used is programmed to eliminate errors across all temperatures.
APPLICATION NOTE: When monitoring a substrate transistor or CPU diode and beta compensation is enabled, the
Ideality Factor should not be adjusted. Beta Compensation automatically corrects for most
ideality errors.
5.7
Diode Faults
The EMC1402 detects an open on the DP and DN pins, and a short across the DP and DN pins. For
each temperature measurement made, the device checks for a diode fault on the external diode
channel(s). When a diode fault is detected, the ALERT pin asserts (unless masked, see Section 5.8)
and the temperature data reads 00h in the MSB and LSB registers (note: the low limit will not be
checked). A diode fault is defined as one of the following: an open between DP and DN, a short from
VDD to DP, or a short from VDD to DN.
If a short occurs across DP and DN or a short occurs from DP to GND, the low limit status bit is set
and the ALERT pin asserts (unless masked). This condition is indistinguishable from a temperature
measurement of 0.000degC (-64°C in extended range) resulting in temperature data of 00h in the MSB
and LSB registers.
If a short from DN to GND occurs (with a diode connected), temperature measurements will continue
as normal with no alerts.
5.8
Consecutive Alerts
The EMC1402 contains multiple consecutive alert counters. One set of counters applies to the ALERT
pin and the second set of counters applies to the THERM pin. Each temperature measurement channel
has a separate consecutive alert counter for each of the ALERT and THERM pins. All counters are
user programmable and determine the number of consecutive measurements that a temperature
channel(s) must be out-of-limit or reporting a diode fault before the corresponding pin is asserted.
See Section 6.11 for more details on the consecutive alert function.
5.9
Digital Filter
To reduce the effect of noise and temperature spikes on the reported temperature, the External Diode
channel uses a programmable digital filter. This filter can be configured as Level 1, Level 2, or
Disabled. The typical filter performance is shown in Figure 5.2 and Figure 5.3.
Revision 2.0 (08-10-12)
18
DATASHEET
SMSC EMC1402
1°C Temperature Sensor with Beta Compensation
Datasheet
Filter Step Response
Temperature (C)
90
Disabled
80
70
Level1
Level2
60
50
40
30
20
10
0
0
2
4
6
8
10
12
14
Samples
Figure 5.2 Temperature Filter Step Response
Filter Impulse Response
90
Temperature (C)
80
Disabled
70
60
50
Level1
40
Level2
30
20
10
0
0
2
4
6
8
10
12
14
Samples
Figure 5.3 Temperature Filter Impulse Response
SMSC EMC1402
19
DATASHEET
Revision 2.0 (08-10-12)
1°C Temperature Sensor with Beta Compensation
Datasheet
5.10
Temperature Monitors
In general, thermal diode temperature measurements are based on the change in forward bias voltage
of a diode when operated at two different currents. This ΔVBE is proportional to absolute temperature
as shown in the following equation:
where:
Δ V BE =
η kT
q
⎞
⎟⎟
⎠
⎛ I
ln ⎜⎜ HIGH
⎝ I LOW
k = Boltzmann’s constant
T = absolute temperature in Kelvin
[1]
q = electron charge
η = diode ideality factor
Figure 5.4 shows a block diagram of the temperature measurement circuit. The negative terminal for
the remote temperature diode, DN, is internally biased with a forward diode voltage referenced to
ground.
IHIGH
ILOW
Substrate
PNP
DP
AntiAliasing
Filter
Resistance
Error
Correction
ΔΣ
ADC
DN
Figure 5.4 Block Diagram of Temperature Monitoring Circuit
5.11
Temperature Measurement Results and Data
The temperature measurement results are stored in the internal and external temperature registers.
These are then compared with the values stored in the high and low limit registers. Both external and
internal temperature measurements are stored in 11-bit format with the eight (8) most significant bits
stored in a high byte register and the three (3) least significant bits stored in the three (3) MSB
positions of the low byte register. All other bits of the low byte register are set to zero.
The EMC1402 has two selectable temperature ranges. The default range is from 0°C to +127°C and
the temperature is represented as binary number able to report a temperature from 0°C to +127.875°C
in 0.125°C steps.
The extended range is an extended temperature range from -64°C to +191°C. The data format is a
binary number offset by 64°C. The extended range is used to measure temperature diodes with a large
known offset (such as AMD processor diodes) where the diode temperature plus the offset would be
equivalent to a temperature higher than +127°C.
Table 5.2 shows the default and extended range formats.
Revision 2.0 (08-10-12)
20
DATASHEET
SMSC EMC1402
1°C Temperature Sensor with Beta Compensation
Datasheet
Table 5.2 Temperature Data Format
TEMPERATURE (°C)
DEFAULT RANGE 0°C TO 127°C
EXTENDED RANGE -64°C TO 191°C
Diode Fault
000 0000 0000
000 0000 0000
-64
000 0000 0000
000 0000 0000
Note 5.2
-1
000 0000 0000
001 1111 1000
0
000 0000 0000
Note 5.1
010 0000 0000
0.125
000 0000 0001
010 0000 0001
1
000 0000 1000
010 0000 1000
64
010 0000 0000
100 0000 0000
65
010 0000 1000
100 0000 1000
127
011 1111 1000
101 1111 1000
127.875
011 1111 1111
101 1111 1111
128
011 1111 1111
Note 5.3
110 0000 0000
190
011 1111 1111
111 1111 0000
191
011 1111 1111
111 1111 1000
>= 191.875
011 1111 1111
111 1111 1111
Note 5.4
5.12
Note 5.1
In default mode, all temperatures < 0°C will be reported as 0°C.
Note 5.2
In the extended range, all temperatures < -64°C will be reported as -64°C.
Note 5.3
For the default range, all temperatures > +127.875°C will be reported as +127.875°C.
Note 5.4
For the extended range, all temperatures > +191.875°C will be reported as +191.875°C.
External Diode Connections
The EMC1402 can be configured to measure a CPU substrate transistor, a discrete 2N3904 thermal
diode, or an AMD processor diode. The diode can be connected in a variety of ways as indicated in
Figure 5.5.
SMSC EMC1402
21
DATASHEET
Revision 2.0 (08-10-12)
1°C Temperature Sensor with Beta Compensation
Datasheet
to
DP
to
DP
to
DP
to
DN
to
DN
to
DN
Local Ground
Typical remote
substrate transistor
i.e. CPU substrate PNP
Typical remote
discrete PNP transistor
i.e. 2N3906
Typical remote
discrete NPN transistor
i.e. 2N3904
Figure 5.5 Diode Configurations
Revision 2.0 (08-10-12)
22
DATASHEET
SMSC EMC1402
1°C Temperature Sensor with Beta Compensation
Datasheet
Chapter 6 Register Description
The registers shown in Table 6.1 are accessible through the SMBus. An entry of ‘-’ indicates that the
bit is not used and will always read ‘0’.
Table 6.1 Register Set in Hexadecimal Order
REGISTER
ADDRESS
R/W
REGISTER NAME
FUNCTION
DEFAULT
VALUE
00h
R
Internal Diode Data
High Byte
Stores the integer data for the
Internal Diode
01h
R
External Diode Data
High Byte
Stores the integer data for the
External Diode
00h
02h
R-C
Status
Stores status bits for the Internal
Diode and External Diodes
00h
Page 25
03h
R/W
Configuration
Controls the general operation of
the device (mirrored at address
09h)
00h
Page 26
04h
R/W
Conversion Rate
Controls the conversion rate for
updating temperature data
(mirrored at address 0Ah)
06h
(4/sec)
Page 27
05h
R/W
Internal Diode High
Limit
Stores the 8-bit high limit for the
Internal Diode (mirrored at address
0Bh)
55h
(85°C)
06h
R/W
Internal Diode Low
Limit
Stores the 8-bit low limit for the
Internal Diode (mirrored at address
0Ch)
00h
(0°C)
55h
(85°C)
PAGE
00h
Page 25
Page 28
07h
R/W
External Diode High
Limit High Byte
Stores the integer portion of the
high limit for the External Diode
(mirrored at register 0Dh)
08h
R/W
External Diode Low
Limit High Byte
Stores the integer portion of the
low limit for the External Diode
(mirrored at register 0Eh)
00h
(0°C)
09h
R/W
Configuration
Controls the general operation of
the device (mirrored at address
03h)
00h
Page 26
0Ah
R/W
Conversion Rate
Controls the conversion rate for
updating temperature data
(mirrored at address 04h)
06h
(4/sec)
Page 27
SMSC EMC1402
23
DATASHEET
Revision 2.0 (08-10-12)
1°C Temperature Sensor with Beta Compensation
Datasheet
Table 6.1 Register Set in Hexadecimal Order (continued)
DEFAULT
VALUE
REGISTER
ADDRESS
R/W
REGISTER NAME
FUNCTION
0Bh
R/W
Internal Diode High
Limit
Stores the 8-bit high limit for the
Internal Diode (mirrored at address
05h)
55h
(85°C)
0Ch
R/W
Internal Diode Low
Limit
Stores the 8-bit low limit for the
Internal Diode (mirrored at address
06h)
00h
(0°C)
55h
(85°C)
PAGE
Page 28
0Dh
R/W
External Diode High
Limit High Byte
Stores the integer portion of the
high limit for the External Diode
(mirrored at register 07h)
0Eh
R/W
External Diode Low
Limit High Byte
Stores the integer portion of the
low limit for the External Diode
(mirrored at register 08h)
00h
(0°C)
0Fh
W
One shot
A write to this register initiates a
one shot update.
00h
Page 29
10h
R
External Diode Data
Low Byte
Stores the fractional data for the
External Diode
00h
Page 25
11h
R/W
Scratchpad
Scratchpad register for software
compatibility
00h
Page 28
12h
R/W
Scratchpad
Scratchpad register for software
compatibility
00h
Page 28
13h
R/W
External Diode High
Limit Low Byte
Stores the fractional portion of the
high limit for the External Diode
00h
14h
R/W
External Diode Low
Limit Low Byte
Stores the fractional portion of the
low limit for the External Diode
00h
19h
R/W
External Diode
THERM Limit
Stores the 8-bit critical temperature
limit for the External Diode
55h
(85°C)
Page 29
1Fh
R/W
Channel Mask
Register
Controls the masking of individual
channels
00h
Page 29
20h
R/W
Internal Diode
THERM Limit
Stores the 8-bit critical temperature
limit for the Internal Diode
55h
(85°C)
21h
R/W
THERM Hysteresis
Stores the 8-bit hysteresis value
that applies to all THERM limits
0Ah
(10°C)
22h
R/W
Consecutive ALERT
Controls the number of out-of-limit
conditions that must occur before
an interrupt is asserted
70h
Page 30
25h
R/W
External Diode 1
Beta Configuration
Stores the Beta Compensation
circuitry settings for External Diode
1
08h
Page 31
27h
R/W
External Diode 1
Ideality Factor
Stores the ideality factor for
External Diode 1
12h
(1.008)
Page 32
29h
R
Internal Diode Data
Low Byte
Stores the fractional data for the
Internal Diode
00h
Page 25
Page 28
Page 29
Revision 2.0 (08-10-12)
24
DATASHEET
SMSC EMC1402
1°C Temperature Sensor with Beta Compensation
Datasheet
Table 6.1 Register Set in Hexadecimal Order (continued)
REGISTER
ADDRESS
R/W
REGISTER NAME
FUNCTION
40h
R/W
Filter Control
FDh
R
FEh
FFh
6.1
DEFAULT
VALUE
PAGE
Controls the digital filter setting for
the External Diode channel
00h
Page 34
Product ID
Stores a fixed value that identifies
each product
Table 6.21
Page 34
R
SMSC ID
Stores a fixed value that
represents SMSC
5Dh
Page 35
R
Revision
Stores a fixed value that
represents the revision number
01h or 04h
Page 35
Data Read Interlock
When any temperature channel high byte register is read, the corresponding low byte is copied into
an internal ‘shadow’ register. The user is free to read the low byte at any time and be guaranteed that
it will correspond to the previously read high byte. Regardless if the low byte is read or not, reading
from the same high byte register again will automatically refresh this stored low byte data.
6.2
Temperature Data Registers
Table 6.2 Temperature Data Registers
ADDR
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
00h
R
Internal Diode
High Byte
128
64
32
16
8
4
2
1
00h
29h
R
Internal Diode
Low Byte
0.5
0.25
0.125
-
-
-
-
-
00h
01h
R
External Diode
High Byte
128
64
32
16
8
4
2
1
00h
10h
R
External Diode
Low Byte
0.5
0.25
0.125
-
-
-
-
-
00h
As shown in Table 6.2, all temperatures are stored as an 11-bit value with the high byte representing
the integer value and the low byte representing the fractional value left justified to occupy the MSBits.
6.3
Status Register
Table 6.3 Status Register
ADDR
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
02h
R-C
Status
BUSY
IHIGH
ILOW
EHIGH
ELOW
FAULT
ETHERM
ITHERM
00h
The Status Register reports the operating status of the Internal Diode and External Diode 1 channels.
When any of the bits are set (excluding the BUSY bit) either the ALERT or THERM pin is being
asserted.
SMSC EMC1402
25
DATASHEET
Revision 2.0 (08-10-12)
1°C Temperature Sensor with Beta Compensation
Datasheet
The ALERT and THERM pins are controlled by the respective consecutive alert counters (see
Section 6.11) and will not be asserted until the programmed consecutive alert count has been reached.
The status bits (except E1THERM and ITHERM) will remain set until read unless the ALERT pin is
configured as a second THERM output (see Section 5.3.2).
Bit 7 - BUSY - This bit indicates that the ADC is currently converting. This bit does not cause either
the ALERT or THERM pins to be asserted.
Bit 6 - IHIGH - This bit is set when the Internal Diode channel exceeds its programmed high limit.
When set, this bit will assert the ALERT pin.
Bit 5 - ILOW - This bit is set when the Internal Diode channel drops below its programmed low limit.
When set, this bit will assert the ALERT pin.
Bit 4 - EHIGH - This bit is set when the External Diode channel exceeds its programmed high limit.
When set, this bit will assert the ALERT pin.
Bit 3 - ELOW - This bit is set when the External Diode channel drops below its programmed low limit.
When set, this bit will assert the ALERT pin.
Bit 2 - FAULT - This bit is asserted when a diode fault is detected. When set, this bit will assert the
ALERT pin.
Bit 1 - ETHERM - This bit is set when the External Diode channel exceeds the programmed THERM
limit. When set, this bit will assert the THERM pin. This bit will remain set until the THERM pin is
released at which point it will be automatically cleared.
Bit 0 - ITHERM - This bit is set when the Internal Diode channel exceeds the programmed THERM
limit. When set, this bit will assert the THERM pin. This bit will remain set until the THERM pin is
released at which point it will be automatically cleared.
6.4
Configuration Register
Table 6.4 Configuration Register
ADDR
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
R/W
Configuration
MASK_
ALL
RUN/
STOP
ALERT/
COMP
RECD
-
RANGE
DAVG_
DIS
-
00h
03h
09h
The Configuration Register controls the basic operation of the device. This register is fully accessible
at either address.
Bit 7 - MASK_ALL - Masks the ALERT pin from asserting.
„
‘0’ (default) - The ALERT pin is not masked. If any of the appropriate status bits are set the ALERT
pin will be asserted.
„
‘1’ - The ALERT pin is masked. It will not be asserted for any interrupt condition unless it is
configured as a secondary THERM pin. The Status Register will be updated normally.
Bit 6 - RUN / STOP - Controls Active/Standby modes.
„
‘0’ (default) - The device is in Active mode and converting on all channels.
„
‘1’ -The device is in Standby mode and not converting.
Bit 5 - ALERT/COMP - Controls the operation of the ALERT pin.
„
‘0’ (default) - The ALERT pin acts as described in Section 5.3.
„
‘1’ - The ALERT pin acts in comparator mode as described in Section 5.3.2. In this mode the
MASK_ALL bit is ignored.
Bit 4 - RECD - Disables the Resistance Error Correction (REC) for External Diode.
„
‘0’ (default)- REC is enabled for the External Diode.
Revision 2.0 (08-10-12)
26
DATASHEET
SMSC EMC1402
1°C Temperature Sensor with Beta Compensation
Datasheet
„
‘1’ - REC is disabled for the External Diode 1.
Bit 2 - RANGE - Configures the measurement range and data format of the temperature channels.
„
‘0’ (default) - The temperature measurement range is 0°C to +127.875°C and the data format is
binary.
„
‘1’ -The temperature measurement range is -64°C to +191.875°C and the data format is offset
binary (see Table 5.2).
Bit 1 - DAVG_DIS - Disables the dynamic averaging feature on all temperature channels.
6.5
„
‘0’ (default) - The dynamic averaging feature is enabled. All temperature channels will be converted
with an averaging factor that is based on the conversion rate as shown in Table 5.1.
„
‘1’ - The dynamic averaging feature is disabled. All temperature channels will be converted with a
maximum averaging factor of 1x (equivalent to 11-bit conversion). For higher conversion rates, this
averaging factor will be reduced as shown in Table 5.1.
Conversion Rate Register
Table 6.5 Conversion Rate Register
ADDR
R/W
REGISTER
B7
B6
B5
B4
R/W
Conversion
Rate
-
-
-
-
04h
0Ah
B3
B2
B1
B0
DEFAULT
06h
(4/sec)
CONV[3:0]
The Conversion Rate Register controls how often the temperature measurement channels are updated
and compared against the limits. This register is fully accessible at either address.
Bits 3-0 - CONV[3:0] - Determines the conversion rate as shown in Table 6.6.
Table 6.6 Conversion Rate
CONV[3:0]
HEX
3
2
1
0
CONVERSIONS / SECOND
0h
0
0
0
0
1 / 16
1h
0
0
0
1
1/8
2h
0
0
1
0
1/4
3h
0
0
1
1
1/2
4h
0
1
0
0
1
5h
0
1
0
1
2
6h
0
1
1
0
4 (default)
7h
0
1
1
1
8
8h
1
0
0
0
16
9h
1
0
0
1
32
Ah
1
0
1
0
64
Bh - Fh
SMSC EMC1402
All others
1
27
DATASHEET
Revision 2.0 (08-10-12)
1°C Temperature Sensor with Beta Compensation
Datasheet
6.6
Limit Registers
Table 6.7 Temperature Limit Registers
ADDR.
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
R/W
Internal Diode
High Limit
128
64
32
16
8
4
2
1
55h
(85°C)
R/W
Internal Diode
Low Limit
128
64
32
16
8
4
2
1
00h
(0°C)
R/W
External
Diode High
Limit High
Byte
128
64
32
16
8
4
2
1
55h
(85°C)
R/W
External
Diode High
Limit Low
Byte
0.5
0.25
0.125
-
-
-
-
-
00h
R/W
External
Diode Low
Limit High
Byte
128
64
32
16
8
4
2
1
00h
(0°C)
R/W
External
Diode Low
Limit Low
Byte
0.5
0.25
0.125
-
-
-
-
-
00h
05h
0Bh
06h
0Ch
07h
0Dh
13h
08h
0Eh
14h
The device contains both high and low limits for all temperature channels. If the measured temperature
exceeds the high limit, then the corresponding status bit is set and the ALERT pin is asserted.
Likewise, if the measured temperature is less than or equal to the low limit, the corresponding status
bit is set and the ALERT pin is asserted.
The data format for the limits must match the selected data format for the temperature so that if the
extended temperature range is used, the limits must be programmed in the extended data format.
The limit registers with multiple addresses are fully accessible at either address.
When the device is in standby mode, updating the limit registers will have no affect until the next
conversion cycle occurs. This can be initiated via a write to the One Shot Register or by clearing the
RUN / STOP bit in the Configuration Register (see Section 6.4).
6.7
Scratchpad Registers
Table 6.8 Scratchpad Register
ADDR
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
11h
R/W
Scratchpad
7
6
5
4
3
2
1
0
00h
12h
R/W
Scratchpad
7
6
5
4
3
2
1
0
00h
The Scratchpad Registers are Read Write registers that are used for place holders to be software
compatible with legacy programs. Reading from the registers will return what is written to them.
Revision 2.0 (08-10-12)
28
DATASHEET
SMSC EMC1402
1°C Temperature Sensor with Beta Compensation
Datasheet
6.8
One Shot Register
Table 6.9 One Shot Register
ADDR.
R/W
REGISTER
0Fh
W
One Shot
B7
B6
B5
B4
B3
B2
B1
B0
Writing to this register initiates a single conversion cycle. Data
is not stored and always reads 00h
DEFAULT
00h
The One Shot Register is used to initiate a one shot command. Writing to the one shot register, when
the device is in standby mode and BUSY bit (in Status Register) is ‘0’, will immediately cause the ADC
to update all temperature measurements. Writing to the One Shot Register while the device is in active
mode will have no affect.
6.9
Therm Limit Registers
Table 6.10 Therm Limit Registers
ADDR.
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
19h
R/W
External
Diode THERM
Limit
128
64
32
16
8
4
2
1
55h
(85°C)
20h
R/W
Internal Diode
THERM Limit
128
64
32
16
8
4
2
1
55h
(85°C)
21h
R/W
THERM
Hysteresis
128
64
32
16
8
4
2
1
0Ah
(10°C)
The THERM Limit Registers are used to determine whether a critical thermal event has occurred. If
the measured temperature exceeds the THERM Limit, then the THERM pin is asserted. The limit
setting must match the chosen data format of the temperature reading registers.
Unlike the ALERT pin, the THERM pin cannot be masked. Additionally, the THERM pin will be released
once the temperature drops below the corresponding threshold minus the THERM Hysteresis.
6.10
Channel Mask Register
Table 6.11 Channel Mask Register
ADDR.
R/W
REGISTER
B7
B6
B5
B4
1Fh
R/W
Channel
Mask
-
-
-
-
B3
B2
B1
B0
DEFAULT
-
-
E
MASK
INT
MASK
00h
The Channel Mask Register controls individual channel masking. When a channel is masked, the
ALERT pin will not be asserted when the masked channel reads a diode fault or out of limit error. The
channel mask does not mask the THERM pin.
Bit 1 - EMASK - Masks the ALERT pin from asserting when the External Diode channel is out of limit
or reports a diode fault.
„
SMSC EMC1402
‘0’ (default) - The External Diode channel will cause the ALERT pin to be asserted if it is out of
limit or reports a diode fault.
29
DATASHEET
Revision 2.0 (08-10-12)
1°C Temperature Sensor with Beta Compensation
Datasheet
„
‘1’ - The External Diode channel will not cause the ALERT pin to be asserted if it is out of limit or
reports a diode fault.
Bit 0 - INTMASK - Masks the ALERT pin from asserting when the Internal Diode temperature is out
of limit.
6.11
„
‘0’ (default) - The Internal Diode channel will cause the ALERT pin to be asserted if it is out of limit.
„
‘1’ - The Internal Diode channel will not cause the ALERT pin to be asserted if it is out of limit.
Consecutive ALERT Register
Table 6.12 Consecutive ALERT Register
ADDR.
R/W
REGISTER
B7
22h
R/W
Consecutive
ALERT
TIME
OUT
B6
B5
B4
CTHRM[2:0]
B3
B2
B1
CALRT[2:0]
B0
DEFAULT
-
70h
The Consecutive ALERT Register determines how many times an out-of-limit error or diode fault must
be detected in consecutive measurements before the ALERT or THERM pin is asserted. Additionally,
the Consecutive ALERT Register controls the SMBus Timeout functionality.
An out-of-limit condition (i.e. HIGH, LOW, or FAULT) occurring on the same temperature channel in
consecutive measurements will increment the consecutive alert counter. The counters will also be reset
if no out-of-limit condition or diode fault condition occurs in a consecutive reading.
When the ALERT pin is configured as an interrupt, when the consecutive alert counter reaches its
programmed value, the following will occur: the STATUS bit(s) for that channel and the last error
condition(s) (i.e. EHIGH) will be set to ‘1’, the ALERT pin will be asserted, the consecutive alert counter
will be cleared, and measurements will continue.
When the ALERT pin is configured as a comparator, the consecutive alert counter will ignore diode
fault and low limit errors and only increment if the measured temperature exceeds the High Limit.
Additionally, once the consecutive alert counter reaches the programmed limit, the ALERT pin will be
asserted, but the counter will not be reset. It will remain set until the temperature drops below the High
Limit minus the THERM Hysteresis value.
For example, if the CALRT[2:0] bits are set for 4 consecutive alerts, the high limits are set at 70°C,
and none of the channels are masked, then the ALERT pin will be asserted after the following four
measurements:
1. Internal Diode reads 71°C and the external diode reads 69°C. Consecutive alert counter for INT is
incremented to 1.
2. Both the Internal Diode and the External Diode read 71°C. Consecutive alert counter for INT is
incremented to 2and for EXT is set to 1.
3. The External Diode reads 71°C and the Internal Diode reads 69°C. Consecutive alert counter for
INT is cleared and EXT is incremented to 2.
4. The Internal Diode reads 71°C and the external diode reads 71°C. Consecutive alert counter for
INT is set to 1 and EXT is incremented to 3.
5. The Internal Diode reads 71°C and the external diode reads 71°C. Consecutive alert counter for
INT is incremented to 2 and EXT is incremented to 4. The appropriate status bits are set for EXT
and the ALERT pin is asserted. EXT counter is reset to 0 and all other counters hold the last value
until the next temperature measurement.
Bit 7 - TIMEOUT - Determines whether the SMBus Timeout function is enabled.
„
‘0’ (default) - The SMBus Timeout feature is disabled. The SMCLK line can be held low indefinitely
without the device resetting its SMBus protocol.
Revision 2.0 (08-10-12)
30
DATASHEET
SMSC EMC1402
1°C Temperature Sensor with Beta Compensation
Datasheet
„
‘1’ - The SMBus Timeout feature is enabled. If the SMCLK line is held low for more than 30ms,
then the device will reset the SMBus protocol.
Bits 6-4 - CTHRM[2:0] - Determines the number of consecutive measurements that must exceed the
corresponding THERM Limit before the THERM pin is asserted. All temperature channels use this
value to set the respective counters. The consecutive THERM counter is incremented whenever any
measurement exceed the corresponding THERM Limit.
If the temperature drops below the THERM limit, then the counter is reset. If a number of consecutive
measurements above the THERM limit occurs, then the THERM pin is asserted low.
Once the THERM pin has been asserted, the consecutive therm counter will not reset until the
corresponding temperature drops below the THERM Limit minus the THERM Hysteresis value.
The bits are decoded as shown in Table 6.13. The default setting is 4 consecutive out of limit
conversions.
Bits 3-1 - CALRT[2:0] - Determine the number of consecutive measurements that must have an out of
limit condition or diode fault before the ALERT pin is asserted. All temperature channels use this value
to set the respective counters. The bits are decoded as shown in Table 6.13. The default setting is 1
consecutive out of limit conversion.
Table 6.13 Consecutive Alert / THERM Settings
6.12
NUMBER OF CONSECUTIVE OUT OF LIMIT
MEASUREMENTS
2
1
0
0
0
0
1
(default for CALRT[2:0])
0
0
1
2
0
1
1
3
1
1
1
4
(default for CTHRM[2:0])
Beta Configuration Registers
Table 6.14 Beta Configuration Registers
ADDR.
R/W
REGISTER
B7
B6
B5
B4
B3
25h
R/W
External
Diode 1 Beta
Configuration
-
-
-
-
ENABLE
B2
B1
B0
BETA[2:0]
DEFAULT
08h
This register is used to set the Beta Compensation factor that is used for the external diode channel.
Bit 3 - ENABLE - Enables the Beta Compensation factor autodetection function.
„
‘0’ - The Beta Compensation Factor autodetection circuitry is disabled. The External Diode will
always use the Beta Compensation factor set by the BETA[2:0] bits.
„
‘1’ (default) - The Beta Compensation factor autodetection circuitry is enabled. At the beginning of
every conversion, the optimal Beta Compensation factor setting will be determined and applied.
The BETA[2:0] bits will be automatically updated to indicate the current setting.
Bit 2-0 - BETA[2:0] - These bits always reflect the current beta configuration settings. If autodetection
circuitry is enabled, then these bits will be updated automatically and writing to these bits will have no
effect. If the autodetection circuitry is disabled, then these bits will determine the beta configuration
setting that is used for their respective channels.
SMSC EMC1402
31
DATASHEET
Revision 2.0 (08-10-12)
1°C Temperature Sensor with Beta Compensation
Datasheet
Care should be taken when setting the BETA[2:0] bits when the autodetection circuitry is disabled. If
the Beta Compensation factor is set at a beta value that is higher than the transistor beta, then the
circuit may introduce measurement errors. When measuring a discrete thermal diode (such as
2N3904) or a CPU diode that functions like a discrete thermal diode (such as an AMD processor
diode), then the BETA[2:0] bits should be set to ‘111b’.
Table 6.15 CPU Beta Values
BETA[2:0]
HEX
ENABLE
2
1
0
0h
0
0
0
0
0.11
1h
0
0
0
1
0.18
2h
0
0
1
0
0.25
3h
0
0
1
1
0.33
4h
0
1
0
0
0.43
5h
0
1
0
1
1.00
6h
0
1
1
0
2.33
7h
0
1
1
1
Disabled
8h - Fh
1
X
X
X
Autodetection
6.13
MINIMUM BETA
External Diode Ideality Factor Registers
Table 6.16 Ideality Configuration Registers
ADDR.
27h
R/W
REGISTER
B7
B6
R/W
External
Diode 1
Ideality
Factor
-
-
B5
B4
B3
B2
B1
IDEALITY[5:0]
B0
DEFAULT
12h
These registers store the ideality factors that are applied to the external diodes. Table 6.17 defines
each setting and the corresponding ideality factor. Beta Compensation and Resistance Error Correction
automatically correct for most diode ideality errors, therefore it is not recommended that these settings
be updated without consulting SMSC.
Table 6.17 Ideality Factor Look-Up Table (Diode Model)
SETTING
FACTOR
SETTING
FACTOR
SETTING
FACTOR
08h
0.9949
18h
1.0159
28h
1.0371
09h
0.9962
19h
1.0172
29h
1.0384
0Ah
0.9975
1Ah
1.0185
2Ah
1.0397
0Bh
0.9988
1Bh
1.0200
2Bh
1.0410
Revision 2.0 (08-10-12)
32
DATASHEET
SMSC EMC1402
1°C Temperature Sensor with Beta Compensation
Datasheet
Table 6.17 Ideality Factor Look-Up Table (Diode Model) (continued)
SETTING
FACTOR
SETTING
FACTOR
SETTING
FACTOR
0Ch
1.0001
1Ch
1.0212
2Ch
1.0423
0Dh
1.0014
1Dh
1.0226
2Dh
1.0436
0Eh
1.0027
1Eh
1.0239
2Eh
1.0449
0Fh
1.0040
1Fh
1.0253
2Fh
1.0462
10h
1.0053
20h
1.0267
30h
1.0475
11h
1.0066
21h
1.0280
31h
1.0488
12h
1.0080
22h
1.0293
32h
1.0501
13h
1.0093
23h
1.0306
33h
1.0514
14h
1.0106
24h
1.0319
34h
1.0527
15h
1.0119
25h
1.0332
35h
1.0540
16h
1.0133
26h
1.0345
36h
1.0553
17h
1.0146
27h
1.0358
37h
1.0566
For CPU substrate transistors that require the BJT transistor model, the ideality factor behaves slightly
differently than for discrete diode-connected transistors. Refer to Table 6.18 when using a CPU
substrate transistor.
Table 6.18 Substrate Diode Ideality Factor Look-Up Table (BJT Model)
SETTING
FACTOR
SETTING
FACTOR
SETTING
FACTOR
08h
0.9869
18h
1.0079
28h
1.0291
09h
0.9882
19h
1.0092
29h
1.0304
0Ah
0.9895
1Ah
1.0105
2Ah
1.0317
0Bh
0.9908
1Bh
1.0120
2Bh
1.0330
0Ch
0.9921
1Ch
1.0132
2Ch
1.0343
0Dh
0.9934
1Dh
1.0146
2Dh
1.0356
0Eh
0.9947
1Eh
1.0159
2Eh
1.0369
0Fh
0.9960
1Fh
1.0173
2Fh
1.0382
10h
0.9973
20h
1.0187
30h
1.0395
11h
0.9986
21h
1.0200
31h
1.0408
12h
1.0000
22h
1.0213
32h
1.0421
13h
1.0013
23h
1.0226
33h
1.0434
14h
1.0026
24h
1.0239
34h
1.0447
15h
1.0039
25h
1.0252
35h
1.0460
16h
1.0053
26h
1.0265
36h
1.0473
SMSC EMC1402
33
DATASHEET
Revision 2.0 (08-10-12)
1°C Temperature Sensor with Beta Compensation
Datasheet
Table 6.18 Substrate Diode Ideality Factor Look-Up Table (BJT Model) (continued)
SETTING
FACTOR
SETTING
FACTOR
SETTING
FACTOR
17h
1.0066
27h
1.0278
37h
1.0486
APPLICATION NOTE: When measuring a 65nm Intel CPUs, the Ideality Setting should be the default 12h. When
measuring 45nm Intel CPUs, the Ideality Setting should be 15h.
6.14
Filter Control Register
Table 6.19 Filter Configuration Register
ADDR.
R/W
REGISTER
B7
B6
B5
B4
B3
B2
40h
R/W
Filter Control
-
-
-
-
-
-
B1
B0
DEFAULT
FILTER[1:0]
00h
The Filter Configuration Register controls the digital filter on the External Diode channel.
Bits 1-0 - FILTER[1:0] - Control the level of digital filtering that is applied to the External Diode
temperature measurements as shown in Table 6.20. See Figure 5.2and Figure 5.3 for examples on the
filter behavior.
Table 6.20 Filter Settings
FILTER[1:0]
6.15
1
0
AVERAGING
0
0
Disabled (default)
0
1
Level 1
1
0
Level 1
1
1
Level 2
Product ID Register
Table 6.21 Product ID Register
ADDR
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
FDh
R
Product ID
0
0
1
0
0
0
0
0
20h
EMC1402
The Product ID Register holds a unique value that identifies the device.
Revision 2.0 (08-10-12)
34
DATASHEET
SMSC EMC1402
1°C Temperature Sensor with Beta Compensation
Datasheet
6.16
SMSC ID Register (FEh)
Table 6.22 Manufacturer ID Register
ADDR.
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
FEh
R
SMSC ID
0
1
0
1
1
1
0
1
5Dh
The Manufacturer ID register contains an 8 bit word that identifies the SMSC as the manufacturer of
the EMC1402.
6.17
Revision Register (FFh)
Table 6.23 Revision Register
ADDR.
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
FFh
R
Revision
0
0
0
0
0
0
0
1
01h
FFh
R
Revision
0
0
0
0
0
1
0
0
04h
The Revision register contains an 8-bit word that identifies the die revision. It can be 01h or 04h.
ENGINEERING NOTE:
SMSC EMC1402
35
DATASHEET
Revision 2.0 (08-10-12)
1°C Temperature Sensor with Beta Compensation
Datasheet
Chapter 7 Typical Operating Curves
Tem perature Error vs. Am bient Tem perature
(2N3904, TDIODE = 42.5°C, VDD = 3.3V)
1.0
1.0
0.8
0.8
0.6
Temperature Error (°C)
Temperature Error (°C)
Tem perature Error vs. Filter Capacitor
(2N3904, TA = 27°C, TDIODE = 27°C, VDD = 3.3V)
0.5
0.3
0.0
-0.3
-0.5
-0.8
-1.0
0
1000
2000
3000
0.4
0.2
0.0
-0.2
-0.4
-0.6
-0.8
4000
-1.0
-40 -25 -10
Filter Capacitor (pF)
5
Temperature Error (°C)
Temperature Error (°C)
Revision 2.0 (08-10-12)
95 110 125
Temperature Error vs. CPU Temperature
Typical 65nm CPU from major vendor
(TA = 27°C, VDD = 3.3V, BETA = 011, CFILTER = 470pF)
Tem perature Error vs. External Diode Tem perature
(2N3904, TA = 42.5°C, VDD = 3.3V)
1.0
0.8
0.6
0.4
0.2
0.0
-0.2
-0.4
-0.6
-0.8
-1.0
-40 -25 -10 5
20 35 50 65 80 95
External Diode Tem perature (°C)
5
20 35 50 65 80
Am bient Tem perature (°C)
4
Beta Compensation
Disabled
3
2
1
0
Beta Compensation Enabled
-1
20
110 125
40
60
80
100
120
CPU Temperature (°C)
36
DATASHEET
SMSC EMC1402
1°C Temperature Sensor with Beta Compensation
Datasheet
S u p p l y C u r r e n t v s. C o n v e r si o n R a te
120
0.8
100
80
REC Disabled
0.6
60
0.4
40
0.2
20
REC Enabled
0.0
0
50
100
Series R (Ohm)
150
1100
1000
900
Supply Current (uA
1.0
1200
Temperature Error (°C)
REC Disabled
Temperature Error (°C)
REC Enabled
Temperature Error vs. Series Resistance
800
D y n a m ic
A v e r a g in g
En a b le d
700
D y n a m ic
A v e r a g in g
D is a b le d
600
500
0
200
400
300
64
32
8
16
4
2
4
2
1/
1
8
1/
/1
6
1
1/
200
C o n v e r si o n R a te
SMSC EMC1402
37
DATASHEET
Revision 2.0 (08-10-12)
D
PIN 1 IDENTIFIER
AREA (D/2 X E1/2)
e
3
DESCRIPTION
-
DATE
RELEASED BY
-
-
SEE SPEC FRONT PAGE FOR REVISION HISTORY
5
Revision 2.0 (08-10-12)
REVISION HISTORY
REVISION
3
c
E
E1
SEE DETAIL "A"
2 8X b
TOP VIEW
END VIEW
38
DATASHEET
A2
A
C
SEATING PLANE
A1
ccc C
SIDE VIEW
3-D VIEW
H
C
NOTES:
1. ALL DIMENSIONS ARE IN MILLIMETER.
2. TOLERANCE ON THE TRUE POSITION OF THE LEADS IS ± 0.065mm MAXIMUM.
3. PACKAGE BODY DIMENSIONS "D" AND "E1" DO NOT INCLUDE MOLD PROTRUSIONS OR FLASH.
MAXIMUM MOLD PROTRUSIONS OR FLASH IS 0.15 mm (0.006 INCHES) PER END AND SIDE.
DIMENSIONS "D" AND "E1" ARE DETERMINED AT DATUM PLANE "H".
4. DIMENSION FOR FOOT LENGTH "L" IS MEASURED AT THE GAUGE PLANE 0.25mm ABOVE THE
SEATING PLANE.
5. DETAILS OF PIN 1 IDENTIFIER ARE OPTIONAL, BUT MUST BE LOCATED WITHIN THE ZONE
INDICATED.
GAUGE PLANE
0.25
SEATING PLANE
0° - 8°
4
L
UNLESS OTHERWISE SPECIFIED
DIMENSIONS ARE IN MILLIMETERS
AND TOLERANCES ARE:
L1
DECIMAL
±0.1
X.X
X.XX ±0.05
X.XXX ±0.025
THIRD ANGLE PROJECTION
80 ARKAY DRIVE
HAUPPAUGE, NY 11788
USA
ANGULAR
±1°
TITLE
DETAIL "A"
NAME
DIM AND TOL PER ASME Y14.5M - 1994
MATERIAL
-
SCALE: 3/1
FINISH
-
DATE
S.K.ILIEV
7/05/04
CHECKED
S.K.ILIEV
S.K.ILIEV
Figure 8.1 8-Pin MSOP / TSSOP Package
REV
DWG NUMBER
MO-8-TSSOP-3x3
7/05/04
APPROVED
PRINT WITH "SCALE TO FIT"
DO NOT SCALE DRAWING
PACKAGE OUTLINE
8 PIN TSSOP, 3x3 MM BODY, 0.65 MM PITCH
DRAWN
SCALE
7/07/04
STD COMPLIANCE
1:1
JEDEC: MO-187 / D
D
SHEET
1 OF 1
SMSC EMC1402
Datasheet
1°C Temperature Sensor with Beta Compensation
Chapter 8 Package Information
1°C Temperature Sensor with Beta Compensation
Datasheet
8.1
Package Markings
All devices will be marked on the first line of the top side with “1402”. On the second line, they will be
marked with the appropriate -X number (-1, -2, etc), the Functional Revision “B” and Country Code
(CC).
SMSC EMC1402
39
DATASHEET
Revision 2.0 (08-10-12)
1°C Temperature Sensor with Beta Compensation
Datasheet
Chapter 9 Datasheet Revision History
Table 9.1 Customer Revision History
REVISION LEVEL & DATE
SECTION/FIGURE/ENTRY
CORRECTION
Rev. 2.0 (08-10-12)
Table 3.3, "SMBus Electrical
Specifications"
Added conditions for tHD:DAT. Data hold time
minimum of 0.3µs is required when receiving from
the master. Data hold time is 0µs min when
transmitting to the master.
Section 6.17, "Revision
Register (FFh)"
Added row to indicate that revision ID can be 04h.
Revision ID may be 04h or 01h.
Table 2.1, "EMC1402 Pin
Description"
In pin description table, added to function column:
“requires pull-up resistor” for SMDATA and SMCLK
pins
Table 2.1, "EMC1402 Pin
Description"
Identified 5V tolerant pins. Added the following
application note below table: “For the 5V tolerant
pins that have a pull-up resistor (SMCLK,
SMDATA, THERM, and ALERT), the voltage
difference between VDD and the pull-up voltage
must never exceed 3.6V.”
Table 3.1, "Absolute
Maximum Ratings"
Updated voltage limits for 5V tolerant pins with
pull-up resistors.
Rev. 1.36
(07-02-09)
Added the following note below table: “For the 5V
tolerant pins that have a pull-up resistor (SMCLK,
SMDATA, THERM, and ALERT), the pull-up
voltage must not exceed 3.6V when the device is
unpowered.”
Table 3.2, "Electrical
Specifications"
Added leakage current.
Rev. 1.35
(04-17-09)
Table 2.1, "EMC1402 Pin
Description"
“Preliminary” removed from table title
Rev. 1.34
(02-27-09)
Table 5.2, "Temperature
Data Format"
Extended range for -1 updated from 001 1111 1111
to 001 1111 1000
Revision 2.0 (08-10-12)
40
DATASHEET
SMSC EMC1402
Similar pages