EMC1412 DATA SHEET (03/14/2014) DOWNLOAD

EMC1412
Multiple Channel 1°C Temperature Sensor with
Beta Compensation
PRODUCT FEATURES
Data Sheet
General Description
Applications
The EMC1412 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) and automatic diode
type detection combine to provide a robust solution for
complex environmental monitoring applications.

The EMC1412 monitors two temperature channels (one
external and one internal). It provides ±1°C accuracy for
both external and internal diode temperatures.
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.
 2014 Microchip Technology Inc.
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Notebook Computers
Desktop Computers
Industrial
Embedded applications
Features
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Programmable SMBus address
Support for diodes requiring the BJT/transistor model
including advanced processor geometries
Automatically determines external diode type and
optimal settings
Resistance Error Correction
External Temperature Monitor
— ±1°C max accuracy (20°C < TDIODE < 110°C)
— 0.125°C resolution
— Supports up to 2.2nF diode filter capacitor

Internal Temperature Monitor
— ±1°C accuracy
— 0.125°C resolution
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3.3V Supply Voltage
Programmable temperature limits for ALERT and
THERM
Available in small 8-pin 2mm x 3mm TDFN RoHS
compliant package
Available in small 8-pin MSOP RoHS compliant
package
DS20005273A-page 1
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
Ordering Information:
ORDERING NUMBER
PACKAGE
FEATURES
SMBUS
ADDRESS
EMC1412-A-ACZL-TR
8-pin MSOP
(RoHS compliant
Two temperature sensors, ALERT and
THERM pins, programmable SMBus address
Selectable via
THERM pull-up
EMC1412-A-AC3-TR
8-pin TDFN 2mm x 3mm
(RoHS compliant
Two temperature sensors, ALERT and
THERM pins, fixed SMBus address
Selectable via
THERM pull-up
EMC1412-1-ACZL-TR
8-pin MSOP
(RoHS compliant
Two temperature sensors, ALERT and
THERM pins, fixed SMBus address
1001_100(r/w)
EMC1412-1-AC3-TR
8-pin TDFN 2mm x 3mm
(RoHS compliant
Two temperature sensors, ALERT and
THERM pins, fixed SMBus address
1001_100(r/w)
EMC1412-2-ACZL-TR
8-pin MSOP
(RoHS compliant
Two temperature sensors, ALERT and
THERM pins, fixed SMBus address
1001_101(r/w)
REEL SIZE IS 4,000 PIECES FOR THE MSOP
REEL SIZE IS 5,000 PIECES FOR THE TDFN
This product meets the halogen maximum concentration values per IEC61249-2-21
TO OUR VALUED CUSTOMERS
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If you have any questions or comments regarding this publication, please contact the Marketing Communications Department via
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Most Current Data Sheet
To obtain the most up-to-date version of this data sheet, please register at our Worldwide Web site at:
http://www.microchip.com
You can determine the version of a data sheet by examining its literature number found on the bottom outside corner of any page.
The last character of the literature number is the version number, (e.g., DS30000000A is version A of document DS30000000).
Errata
An errata sheet, describing minor operational differences from the data sheet and recommended workarounds, may exist for current devices. As device/documentation issues become known to us, we will publish an errata sheet. The errata will specify the
revision of silicon and revision of document to which it applies.
To determine if an errata sheet exists for a particular device, please check with one of the following:
• Microchip’s Worldwide Web site; http://www.microchip.com
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When contacting a sales office, please specify which device, revision of silicon and data sheet (include -literature number) you are
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DS20005273A-page 2
 2014 Microchip Technology Inc.
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
Table of Contents
Chapter 1 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Chapter 2 Delta . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1
Functional Delta from EMC1412 rev A to rev B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Chapter 3 Pin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Chapter 4 Electrical Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4.1
4.2
4.3
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
SMBus Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Chapter 5 System Management Bus Interface Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.1
5.2
5.3
Communications Protocol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.1.1
SMBus Start Bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.1.2
SMBus Address and RD / WR Bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.1.3
THERM Pin Considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.1.4
SMBus Data Bytes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.1.5
SMBus ACK and NACK Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.1.6
SMBus Stop Bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.1.7
SMBus Timeout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.1.8
SMBus and I2C Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SMBus Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.2.1
Write Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.2.2
Read Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.2.3
Send Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.2.4
Receive Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Alert Response Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13
13
13
14
14
14
15
15
15
15
15
16
16
16
16
Chapter 6 Product Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
6.1
6.2
6.3
6.4
6.5
6.6
6.7
6.8
6.9
Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.1.1
Conversion Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.1.2
Dynamic Averaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
THERM Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ALERT Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.1
ALERT Pin Interrupt Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.2
ALERT Pin Comparator Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Temperature Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.4.1
Beta Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.4.2
Resistance Error Correction (REC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.4.3
Programmable External Diode Ideality Factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Diode Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Consecutive Alerts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Digital Filter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Temperature Measurement Results and Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
External Diode Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
18
18
19
19
20
20
20
20
20
21
21
21
21
21
23
24
Chapter 7 Register Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
7.1
7.2
Data Read Interlock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Temperature Data Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
 2014 Microchip Technology Inc.
DS20005273A-page 3
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
7.3
7.4
7.5
7.6
7.7
7.8
7.9
7.10
7.11
7.12
7.13
7.14
7.15
7.16
7.17
Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Conversion Rate Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Limit Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Scratchpad Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
One Shot Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Therm Limit Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Channel Mask Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Consecutive ALERT Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Beta Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
External Diode Ideality Factor Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Filter Control Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Product ID Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Microchip ID Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Revision Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
27
28
29
30
30
31
31
31
32
33
34
36
36
36
37
Chapter 8 Typical Operating Curves. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Chapter 9 Package Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
9.1
Package Markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Chapter 10 Data Sheet Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
DS20005273A-page 4
 2014 Microchip Technology Inc.
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
List of Figures
Figure 1.1
Figure 3.1
Figure 3.2
Figure 5.1
Figure 5.2
Figure 6.1
Figure 6.2
Figure 6.3
Figure 6.4
Figure 9.1
Figure 9.2
Figure 9.3
Figure 9.4
Figure 9.5
EMC1412 Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
EMC1412 Pin Diagram, MSOP-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
EMC1412 Pin Diagram, TDFN-8 2mm x 3mm. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
SMBus Timing Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Isolating THERM Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
System Diagram for EMC1412 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Temperature Filter Step Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Temperature Filter Impulse Response. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Diode Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
EMC1412 2mm x 3mm TDFN Package Drawing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
8-Pin MSOP / TSSOP Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
EMC1412-1 8-Pin TDFN Package Markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
EMC1412-A 8-Pin TDFN Package Markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
EMC1412 8-Pin MSOP Package Markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
 2014 Microchip Technology Inc.
DS20005273A-page 5
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
List of Tables
Table 3.1 EMC1412 Pin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Table 3.2 Pin Types. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Table 4.1 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Table 4.2 Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Table 4.3 SMBus Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Table 5.1 SMBus Address Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Table 5.2 Protocol Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Table 5.3 Write Byte Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Table 5.4 Read Byte Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Table 5.5 Send Byte Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Table 5.6 Receive Byte Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Table 5.7 Alert Response Address Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Table 6.1 Supply Current vs. Conversion Rate for EMC1412 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Table 6.2 Temperature Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Table 7.1 Register Set in Hexadecimal Order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Table 7.2 Temperature Data Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Table 7.3 Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Table 7.4 Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Table 7.5 Conversion Rate Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Table 7.6 Conversion Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Table 7.7 Temperature Limit Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Table 7.8 Scratchpad Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Table 7.9 One Shot Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Table 7.10 Therm Limit Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Table 7.11 Channel Mask Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Table 7.12 Consecutive ALERT Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Table 7.13 Consecutive Alert / Therm Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Table 7.14 Beta Configuration Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Table 7.15 CPU Beta Values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Table 7.16 Ideality Configuration Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Table 7.17 Ideality Factor Look-Up Table (Diode Model) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Table 7.18 Substrate Diode Ideality Factor Look-Up Table (BJT Model) . . . . . . . . . . . . . . . . . . . . . . . . . 35
Table 7.19 Filter Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Table 7.20 FILTER Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Table 7.21 Product ID Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Table 7.22 Manufacturer ID Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Table 7.23 Revision Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Table 10.1 Revision History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
DS20005273A-page 6
 2014 Microchip Technology Inc.
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
Chapter 1 Block Diagram
Figure 1.1 EMC1412 Block Diagram
Chapter 2 Delta
2.1
Functional Delta from EMC1412 rev A to rev B
1. Updated revision number to 04h.
 2014 Microchip Technology Inc.
DS20005273A-page 7
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
Chapter 3 Pin Description
Figure 3.1 EMC1412 Pin Diagram, MSOP-8
Figure 3.2 EMC1412 Pin Diagram, TDFN-8 2mm x 3mm
Table 3.1 EMC1412 Pin Description
PIN NUMBER
NAME
1
VDD
2
DP
External diode positive (anode) connection
AIO
3
DN
External diode negative (cathode) connection
AIO
4
THERM / ADDR
5
GND
6
ALERT
DS20005273A-page 8
FUNCTION
TYPE
Power supply
Power
THERM - Active low Critical THERM output
signal - requires pull-up resistor
OD (5V)
ADDR - Selects SMBus address based on pullup resistor
OD (5V)
Ground
Active low digital ALERT output signal requires pull-up resistor
Power
OD (5V)
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Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
Table 3.1 EMC1412 Pin Description (continued)
PIN NUMBER
NAME
FUNCTION
7
SMDATA
SMBus Data input/output - requires pull-up
resistor
8
SMCLK
SMBus Clock input - requires pull-up resistor
Bottom Pad
Exposed Pad
Not internally connected, but recommend
grounding.
TYPE
DIOD (5V)
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 Table 3.2.
Table 3.2 Pin Types
PIN TYPE
Power
AIO
DI
DESCRIPTION
This pin is used to supply power or ground to the device.
Analog Input / Output -This pin is used as an I/O for analog signals.
Digital Input - This pin is used as a digital input. This pin is 5V tolerant.
DIOD
Digital Input / Open Drain Output - This pin is used as a digital I/O. When it is used as
an output, it is open drain and requires a pull-up resistor. This pin is 5V tolerant.
OD
Open Drain Digital Output - This pin is used as a digital output. It is open drain and
requires a pull-up resistor. This pin is 5V tolerant.
 2014 Microchip Technology Inc.
DS20005273A-page 9
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
Chapter 4 Electrical Specifications
4.1
Absolute Maximum Ratings
Table 4.1 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
0 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 5V tolerant pins (|V5VT_pin - VDD|) (see Note 4.1)
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 (j-a)
140.8
°C/W
89
°C/W
2000
V
Package Thermal Characteristics for TDFN-8
Thermal Resistance (j-a)
ESD Rating, All pins HBM
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.
Note 4.1
DS20005273A-page 10
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.
 2014 Microchip Technology Inc.
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
4.2
Electrical Specifications
Table 4.2 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
μA
1 conversion / sec, dynamic
averaging disabled
930
1200
μA
4 conversions / sec, dynamic
averaging enabled
μA
> 16 conversions / sec, dynamic
averaging enabled
μA
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
default settings
nF
Connected across external diode
Conversion Time all
Channels
tCONV
190
Capacitive Filter
CFILTER
2.2
2.7
ALERT and THERM pins
Output Low Voltage
VOL
Leakage Current
ILEAK
 2014 Microchip Technology Inc.
0.4
±5
V
ISINK = 8mA
μA
ALERT and THERM pins
Device powered or unpowered
TA < 85°C
pull-up voltage < 3.6V
DS20005273A-page 11
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
4.3
SMBus Electrical Characteristics
Table 4.3 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
Leakage Current
ILEAK
±5
μA
Powered or unpowered
TA < 85°C
Hysteresis
Input Capacitance
CIN
Output Low Sink Current
IOL
8.2
420
mV
5
pF
15
mA
SMDATA = 0.4V
SMBus Timing
Clock Frequency
fSMB
Spike Suppression
tSP
Bus Free Time Stop to
Start
tBUF
1.3
μs
Hold Time: Start
tHD:STA
0.6
μs
Setup Time: Start
tSU:STA
0.6
μs
Setup Time: Stop
tSU:STO
0.6
μs
Data Hold Time
tHD:DAT
0
μs
When transmitting to the master
Data Hold Time
tHD:DAT
0.3
μs
When receiving from the master
Data Setup Time
tSU:DAT
100
ns
Clock Low Period
tLOW
1.3
μs
Clock High Period
tHIGH
0.6
μs
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
DS20005273A-page 12
10
400
kHz
50
ns
 2014 Microchip Technology Inc.
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
Chapter 5 System Management Bus Interface Protocol
5.1
Communications Protocol
The EMC1412 communicates with a host controller, such as a Microchip 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 5.1.
For the first 15ms after power-up the device may not respond to SMBus communications.
.
Figure 5.1 SMBus Timing Diagram
5.1.1
SMBus Start Bit
The SMBus Start bit is defined as a transition of the SMBus Data line from a logic ‘1’ state to a logic
‘0’ state while the SMBus Clock line is in a logic ‘1’ state.
5.1.2
SMBus Address and RD / WR Bit
The SMBus Address Byte consists of the 7-bit client address followed by the RD / WR indicator bit. If
this RD / WR bit is a logic ‘0’, the SMBus Host is writing data to the client device. If this RD / WR bit
is a logic ‘1’, the SMBus Host is reading data from the client device.
The EMC1412-A SMBus slave address is determined by the pull-up resistor on the THERM pin as
shown in Table 5.1, "SMBus Address Decode".
The Address decode is performed by pulling known currents from VDD through the external resistor
causing the pin voltage to drop based on the respective current / resistor relationship. This pin voltage
is compared against a threshold that determines the value of the pull-up resistor.
Table 5.1 SMBus Address Decode
 2014 Microchip Technology Inc.
PULL UP RESISTOR ON
THERM PIN (±5%)
SMBUS ADDRESS
4.7k
1111_100(r/w)b
6.8k
1011_100(r/w)b
10k
1001_100(r/w)b
DS20005273A-page 13
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
Table 5.1 SMBus Address Decode (continued)
PULL UP RESISTOR ON
THERM PIN (±5%)
SMBUS ADDRESS
15k
1101_100(r/w)b
22k
0011_100(r/w)b
33k
0111_100(r/w)b
The EMC1412-1 SMBus address is hard coded to 1001_100(r/w).
The EMC1412-2 SMBus address is hard coded to 1001_101(r/w).
5.1.3
THERM Pin Considerations
Because of the decode method used to determine the SMBus Address, it is important that the pull-up
resistance on the THERM pin be within the tolerances shown in Table 5.1. Additionally, the pull-up
resistor on the THERM pin must be connected to the same 3.3V supply that drives the VDD pin.
For 15ms after power up, the THERM pin must not be pulled low or the SMBus address will not be
decoded properly. If the system requirements do not permit these conditions, the THERM pin must be
isolated from its hard-wired OR’d bus during this time.
One method of isolating this pin is shown in Figure 5.2.
Figure 5.2 Isolating THERM Pin
5.1.4
SMBus Data Bytes
All SMBus Data bytes are sent most significant bit first and composed of 8-bits of information.
5.1.5
SMBus ACK and NACK Bits
The SMBus client will acknowledge all data bytes that it receives. This is done by the client device
pulling the SMBus data line low after the 8th bit of each byte that is transmitted. This applies to the
Write Byte protocol.
The Host will NACK (not acknowledge) the last data byte to be received from the client by holding the
SMBus data line high after the 8th data bit has been sent.
DS20005273A-page 14
 2014 Microchip Technology Inc.
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
5.1.6
SMBus Stop Bit
The SMBus Stop bit is defined as a transition of the SMBus Data line from a logic ‘0’ state to a logic
‘1’ state while the SMBus clock line is in a logic ‘1’ state. When the device detects an SMBus Stop bit
and it has been communicating with the SMBus protocol, it will reset its client interface and prepare
to receive further communications.
5.1.7
SMBus Timeout
The EMC1412 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 7.11).
5.1.8
SMBus and I2C Compatibility
The EMC1412 is compatible with SMBus and I2C. The major differences between SMBus and I2C
devices are highlighted here. For more information, refer to the SMBus 2.0 and I2C specifications. For
information on using the EMC1412 in an I2C system, refer to AN 14.0 Dedicated Slave Devices in I2C
Systems.
1. EMC1412 supports I2C fast mode at 400kHz. This covers the SMBus max time of 100kHz.
2. Minimum frequency for SMBus communications is 10kHz.
3. The SMBus client protocol will reset if the clock is held at a logic ‘0’ for longer than 30ms. This
timeout functionality is disabled by default in the EMC1412 and can be enabled by writing to the
TIMEOUT bit. I2C does not have a timeout.
4. I2C devices do not support the Alert Response Address functionality (which is optional for SMBus).
Attempting to communicate with the EMC1412 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.
5.2
SMBus Protocols
The device supports 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 5.2.
Table 5.2 Protocol Format
5.2.1
DATA SENT
TO DEVICE
DATA SENT TO
THE HOST
# of bits sent
# of bits sent
Write Byte
The Write Byte is used to write one byte of data to the registers, as shown in Table 5.3.
Table 5.3 Write Byte Protocol
START
SLAVE
ADDRESS
WR
ACK
REGISTER
ADDRESS
ACK
REGISTER
DATA
ACK
STOP
1 -> 0
YYYY_YYY
0
0
XXh
0
XXh
0
0 -> 1
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DS20005273A-page 15
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
5.2.2
Read Byte
The Read Byte protocol is used to read one byte of data from the registers as shown in Table 5.4.
Table 5.4 Read Byte Protocol
START
SLAVE
ADDRESS
WR
ACK
REGISTER
ADDRESS
ACK
START
SLAVE
ADDRESS
RD
ACK
REGISTER
DATA
NACK
STOP
1 -> 0
YYYY_
YYY
0
0
XXh
0
1 -> 0
YYYY_
YYY
1
0
XX
1
0 -> 1
5.2.3
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 5.5.
Table 5.5 Send Byte Protocol
START
SLAVE
ADDRESS
WR
ACK
REGISTER
ADDRESS
ACK
STOP
1 -> 0
YYYY_YYY
0
0
XXh
0
0 -> 1
5.2.4
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 5.6.
Table 5.6 Receive Byte Protocol
START
SLAVE
ADDRESS
RD
ACK
REGISTER DATA
NACK
STOP
1 -> 0
YYYY_YYY
1
0
XXh
1
0 -> 1
5.3
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 5.7.
Table 5.7 Alert Response Address Protocol
START
ALERT
RESPONSE
ADDRESS
RD
ACK
DEVICE
ADDRESS
NACK
STOP
1 -> 0
0001_100
1
0
YYYY_YYY
1
0 -> 1
DS20005273A-page 16
 2014 Microchip Technology Inc.
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
The EMC1412 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.
 2014 Microchip Technology Inc.
DS20005273A-page 17
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
Chapter 6 Product Description
The EMC1412 is an SMBus temperature sensor. The EMC1412 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 EMC1412 and using
that data to control the speed of one or more fans.
The EMC1412 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 EMC1412 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.
Figure 6.1 shows a system level block diagram of the EMC1412.
Figure 6.1 System Diagram for EMC1412
6.1
Modes of Operation
The EMC1412 has two modes of operation.
6.1.1

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.
Conversion Rates
The EMC1412 may be configured for different conversion rates based on the system requirements.
The conversion rate is configured as described in Section 7.5. The default conversion rate is 4
conversions per second. Other available conversion rates are shown in Table 7.6, "Conversion Rate".
DS20005273A-page 18
 2014 Microchip Technology Inc.
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
6.1.2
Dynamic Averaging
Dynamic averaging causes the EMC1412 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 7.4, "Configuration Register"). 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 6.1.
Table 6.1 Supply Current vs. Conversion Rate for EMC1412
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
6.2
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).
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.
 2014 Microchip Technology Inc.
DS20005273A-page 19
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
6.3
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 7.4).
6.3.1
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_ALL bit. Once the ALERT pin has been masked,
it will be de-asserted and remain de-asserted until the MASK_ALL bit is cleared by the user. Any
interrupt conditions that occur while the ALERT pin is masked will update the Status Register normally.
There are also individual channel masks (see Section 7.10).
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.
6.3.2
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_ALL bit will not block the ALERT pin in this mode; however, the individual channel masks
(see Section 7.10) will prevent the respective channel from asserting the ALERT pin.
6.4
Temperature Measurement
The EMC1412 can monitor the temperature of one externally connected diode. The external diode
channel is configured with Resistance Error Correction and Beta Compensation based on user settings
and system requirements.
The device contains programmable High, Low, and Therm limits for all measured temperature
channels. If the measured temperature goes below the Low limit or above the High limit, the ALERT
pin can be asserted (based on user settings). If the measured temperature meets or exceeds the
Therm Limit, the THERM pin is asserted unconditionally, providing two tiers of temperature detection.
6.4.1
Beta Compensation
The EMC1412 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.
DS20005273A-page 20
 2014 Microchip Technology Inc.
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
6.4.2
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
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 EMC1412 automatically corrects up to 100 ohms
of series resistance.
6.4.3
Programmable External Diode Ideality Factor
The EMC1412 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 EMC1412 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.
6.5
Diode Faults
The EMC1412 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 6.6)
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 0.000°C (-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.
6.6
Consecutive Alerts
The EMC1412 contain 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 7.11, "Consecutive ALERT Register" for more details on the consecutive alert function.
6.7
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
(default) (see Section 7.14). The typical filter performance is shown in Figure 6.2 and Figure 6.3.
 2014 Microchip Technology Inc.
DS20005273A-page 21
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
Figure 6.2 Temperature Filter Step Response
Figure 6.3 Temperature Filter Impulse Response
DS20005273A-page 22
 2014 Microchip Technology Inc.
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
6.8
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 EMC1412 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 6.2 shows the default and extended range formats.
Table 6.2 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 6.2
-1
000 0000 0000
001 1111 1000
0
000 0000 0000
Note 6.1
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 6.3
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 6.4
Note 6.1
In default mode, all temperatures < 0°C will be reported as 0°C.
Note 6.2
In the extended range, all temperatures < -64°C will be reported as -64°C.
Note 6.3
For the default range, all temperatures > +127.875°C will be reported as +127.875°C.
Note 6.4
For the extended range, all temperatures > +191.875°C will be reported as +191.875°C.
 2014 Microchip Technology Inc.
DS20005273A-page 23
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
6.9
External Diode Connections
The EMC1412 can be configured to measure a CPU substrate transistor, a discrete 2N3904 thermal
diode, or an AMD processor diode. The diodes can be connected as indicated in Figure 6.4.
Figure 6.4 Diode Configurations
DS20005273A-page 24
 2014 Microchip Technology Inc.
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
Chapter 7 Register Description
The registers shown in Table 7.1 are accessible through the SMBus. An entry of ‘-’ indicates that the
bit is not used and will always read ‘0’.
Table 7.1 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
00h
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 Diode
00h
Page 27
03h
R/W
Configuration
Controls the general operation of
the device (mirrored at address
09h)
00h
Page 28
04h
R/W
Conversion Rate
Controls the conversion rate for
updating temperature data
(mirrored at address 0Ah)
06h
(4/sec)
Page 29
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
Page 27
Page 30
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 28
0Ah
R/W
Conversion Rate
Controls the conversion rate for
updating temperature data
(mirrored at address 04h)
06h
(4/sec)
Page 29
 2014 Microchip Technology Inc.
DS20005273A-page 25
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
Table 7.1 Register Set in Hexadecimal Order (continued)
REGISTER
ADDRESS
R/W
REGISTER NAME
FUNCTION
DEFAULT
VALUE
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 30
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 31
10h
R
External Diode Data
Low Byte
Stores the fractional data for the
External Diode
00h
Page 27
11h
R/W
Scratchpad
Scratchpad register for software
compatibility
00h
Page 30
12h
R/W
Scratchpad
Scratchpad register for software
compatibility
00h
Page 30
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 31
1Fh
R/W
Channel Mask
Register
Controls the masking of individual
channels
00h
Page 31
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 32
25h
R/W
External Diode Beta
Configuration
Stores the Beta Compensation
circuitry settings for External Diode
08h
Page 33
27h
R/W
External Diode
Ideality Factor
Stores the ideality factor for the
External Diode
12h
(1.008)
Page 34
29h
R
Internal Diode Data
Low Byte
Stores the fractional data for the
Internal Diode
00h
Page 27
40h
R/W
Filter Control
Controls the digital filter setting for
the External Diode channel
00h
Page 36
DS20005273A-page 26
Page 30
Page 31
 2014 Microchip Technology Inc.
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
Table 7.1 Register Set in Hexadecimal Order (continued)
REGISTER
ADDRESS
R/W
REGISTER NAME
FUNCTION
FDh
R
Product ID
FEh
R
FFh
R
7.1
DEFAULT
VALUE
PAGE
Stores a fixed value that identifies
the device
20h
Page 36
Manufacturer ID
Stores a fixed value that
represents Microchip
5Dh
Page 36
Revision
Stores a fixed value that
represents the revision number
04h
Page 37
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.
7.2
Temperature Data Registers
Table 7.2 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 7.2, 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.
7.3
Status Register
Table 7.3 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 channels.
When any of the bits are set (excluding the BUSY bit) either the ALERT or THERM pin is being
asserted.
The ALERT and THERM pins are controlled by the respective consecutive alert counters (see
Section 7.11) and will not be asserted until the programmed consecutive alert count has been reached.
 2014 Microchip Technology Inc.
DS20005273A-page 27
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
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 6.3.2).
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.
7.4
Configuration Register
Table 7.4 Configuration Register
ADDR
03h
09h
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
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 in comparator mode. 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 6.3.

‘1’ - The ALERT pin acts in comparator mode as described in Section 6.3.2. In this mode the
MASK_ALL bit is ignored.
Bit 4 - RECD - Disables the Resistance Error Correction (REC) for the External Diode.

‘0’ (default) - REC is enabled for the External Diode.

‘1’ - REC is disabled for the External Diode.
DS20005273A-page 28
 2014 Microchip Technology Inc.
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
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 6.2).
Bit 1 - DAVG_DIS - Disables the dynamic averaging feature on all temperature channels.
7.5

‘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 6.1.

‘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 6.1.
Conversion Rate Register
Table 7.5 Conversion Rate Register
ADDR
04h
0Ah
R/W
REGISTER
B7
B6
B5
B4
R/W
Conversion
Rate
-
-
-
-
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 7.6.
Table 7.6 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
 2014 Microchip Technology Inc.
All others
1
DS20005273A-page 29
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
7.6
Limit Registers
Table 7.7 Temperature Limit Registers
ADDR.
05h
0Bh
06h
0Ch
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
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 effect 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 7.4).
7.7
Scratchpad Registers
Table 7.8 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.
DS20005273A-page 30
 2014 Microchip Technology Inc.
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
7.8
One Shot Register
Table 7.9 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 effect.
7.9
Therm Limit Registers
Table 7.10 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, 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.
7.10
Channel Mask Register
Table 7.11 Channel Mask Register
ADDR.
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
1Fh
R/W
Channel
Mask
-
-
-
-
-
-
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.

‘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.
 2014 Microchip Technology Inc.
DS20005273A-page 31
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet

‘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.
7.11

‘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 7.12 Consecutive ALERT Register
ADDR.
R/W
REGISTER
B7
22h
R/W
Consecutive
ALERT
TIME
OUT
B6
B5
CTHRM[2:0]
B4
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 on an EMC1412 device, 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 2 and for EXT is set to 1.
3. The External Diode reads 71°C and the Internal Diode read 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.
DS20005273A-page 32
 2014 Microchip Technology Inc.
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet

‘1’ - The SMBus Timeout feature is enabled. If the SMCLK line is held low for more than 30ms,
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, the counter is reset. If a number of consecutive
measurements above the Therm Limit occurs, 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 7.13. 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 7.13. The default setting is 1
consecutive out of limit conversion.
Table 7.13 Consecutive Alert / Therm Settings
7.12
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 Register
Table 7.14 Beta Configuration Register
ADDR.
R/W
REGISTER
B7
B6
B5
B4
B3
25h
R/W
External
Diode 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 auto-detection function.

‘0’ - The Beta Compensation Factor auto-detection circuitry is disabled.

‘1’ (default) - The Beta Compensation factor auto-detection 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 auto-detection
circuitry is enabled, these bits will be updated automatically and writing to these bits will have no effect.
If the auto-detection circuitry is disabled, these bits will determine the beta configuration setting.
Care should be taken when setting the BETA[2:0] bits when the auto-detection circuitry is disabled. If
the Beta Compensation factor is set at a beta value that is higher than the transistor beta, the circuit
 2014 Microchip Technology Inc.
DS20005273A-page 33
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
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), the
BETA[2:0] bits should be set to ‘111b’.
Table 7.15 CPU Beta Values
BETA[2:0]
HEX
ENABLEX
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
Auto-detection
7.13
MINIMUM BETA
External Diode Ideality Factor Register
Table 7.16 Ideality Configuration Registers
ADDR.
27h
R/W
REGISTER
B7
B6
R/W
External
Diode
Ideality
Factor
-
-
B5
B4
B3
B2
B1
IDEALITY[5:0]
B0
DEFAULT
12h
This register stores the ideality factors that are applied to the external diode. Table 7.17 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 Microchip.
Table 7.17 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
0Ch
1.0001
1Ch
1.0212
2Ch
1.0423
DS20005273A-page 34
 2014 Microchip Technology Inc.
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
Table 7.17 Ideality Factor Look-Up Table (Diode Model) (continued)
SETTING
FACTOR
SETTING
FACTOR
SETTING
FACTOR
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 7.18 when using a CPU
substrate transistor.
Table 7.18 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
17h
1.0066
27h
1.0278
37h
1.0486
 2014 Microchip Technology Inc.
DS20005273A-page 35
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
APPLICATION NOTE: When measuring a 65nm Intel CPU, the Ideality Setting should be the default 12h. When
measuring a 45nm Intel CPU, the Ideality Setting should be 15h.
7.14
Filter Control Register
Table 7.19 Filter Configuration Register
ADDR.
R/W
REGISTER
B7
B6
B5
B4
B3
B2
40h
R/W
Filter Control
-
-
-
-
-
-
B1
B0
FILTER[1:0]
DEFAULT
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 measurement as shown in Table 7.20. See Figure 6.2 and Figure 6.3 for examples on the
filter behavior.
Table 7.20 FILTER Decode
FILTER[1:0]
7.15
1
0
AVERAGING
0
0
Disabled (default)
0
1
Level 1
1
0
Level 1
1
1
Level 2
Product ID Register
Table 7.21 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
The Product ID Register holds a unique value that identifies the device.
7.16
Microchip ID Register
Table 7.22 Manufacturer ID Register
ADDR.
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
FEh
R
MCHP ID
0
1
0
1
1
1
0
1
5Dh
The Manufacturer ID register contains an 8-bit word that identifies Microchip as the manufacturer of
the EMC1412.
DS20005273A-page 36
 2014 Microchip Technology Inc.
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
7.17
Revision Register
Table 7.23 Revision Register
ADDR.
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
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.
 2014 Microchip Technology Inc.
DS20005273A-page 37
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
Chapter 8 Typical Operating Curves
DS20005273A-page 38
 2014 Microchip Technology Inc.
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
 2014 Microchip Technology Inc.
DS20005273A-page 39
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
http://www.microchip.com/packaging
Note: For the most current package drawings,
see the Microchip Packaging Specification at
Chapter 9 Package Information
Figure 9.1 EMC1412 2mm x 3mm TDFN Package Drawing
DS20005273A-page 40
 2014 Microchip Technology Inc.
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
Note: For the most current package drawings, see the Microchip Packaging Specification at
http://www.microchip.com/packaging.
Figure 9.2 8-Pin MSOP / TSSOP Package
 2014 Microchip Technology Inc.
DS20005273A-page 41
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
9.1
Package Markings
The devices will be marked as shown in Figure 9.3, Figure 9.4 and Figure 9.5.
Figure 9.3 EMC1412-1 8-Pin TDFN Package Markings
DS20005273A-page 42
 2014 Microchip Technology Inc.
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
Figure 9.4 EMC1412-A 8-Pin TDFN Package Markings
 2014 Microchip Technology Inc.
DS20005273A-page 43
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
Figure 9.5 EMC1412 8-Pin MSOP Package Markings
DS20005273A-page 44
 2014 Microchip Technology Inc.
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
Chapter 10 Data Sheet Revision History
Table 10.1 Revision History
REVISION LEVEL & DATE
REV A (03-03-14)
SECTION/FIGURE/ENTRY
CORRECTION
REV A replaces previous SMSC version Rev. 1.41 (02-23-12)
Rev. 1.41 (02-23-12)
Chapter 3, Pin Description
Labeled exposed pad in pinout figure and added
row in pin description table. Recommendation is to
ground the exposed pad.
Rev. 1.40 (01-05-12)
Table 4.3, "SMBus Electrical
Specifications"
Added conditions for tHD:DAT. Data hold time
minimum of 0.3μs is required when receiving from
the master.
Section 5.1.8, "SMBus and
I2C Compatibility"
Renamed from “SMBus and I2C Compliance.” First
paragraph, added first sentence: “The EMC1412 is
compatible with SMBus and I2C.”
And added last sentence: “For information on
using the EMC1412 in an I2C system, refer to AN
14.0 SMSC Dedicated Slave Devices in I2C
Systems.”
Table 4.2, "Electrical
Specifications"
Filter MAX changed from “2.5nF” to “2.7nF”.
Section 7.17, "Revision
Register"
Set revision ID to 04h.
Chapter 5, System
Management Bus Interface
Protocol
Updated error on ACK bit settings and reorganized
chapter information and moved ALERT pin
considerations.
Chapter 6, Product
Description
Reorganized information for temperature
monitoring and ALERT pin considerations.
Rev. 1.37 (12-23-09)
Section 7.17, "Revision
Register"
Changed default from 01h to 03h to match the
actual value.
Rev. 1.36 (09-19-09)
Ordering Information
Added EMC1412-1-AC3-TR in an 8-pin TDFN
package.
Section 4.1, "Absolute
Maximum Ratings"
Updated voltage on 5V tolerant pins with pull up
from -0.3 to 3.6 to 0 to 3.6. Added thermal
characteristics for TDFN package.
Chapter 9, Package
Information
Added package information for the TDFN.
Section 9.1, "Package
Markings"
Added package marking information for the TDFN.
Pin Table
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, ALERT), the voltage difference
between VDD and the pull-up voltage must never
exceed 3.6V.”
Rev. 1.38 (09-30-10)
Rev. 1.35 (05-06-09)
 2014 Microchip Technology Inc.
DS20005273A-page 45
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
Table 10.1 Revision History (continued)
REVISION LEVEL & DATE
SECTION/FIGURE/ENTRY
Table 4.1, "Absolute
Maximum Ratings"
CORRECTION
Updated voltage limits for 5V tolerant pins with
pull-up resistors.
Added the following note below table: “For the 5V
tolerant pins that have a pull-up resistor (SMCLK,
SMDATA, THERM, ALERT), the pull-up voltage
must not exceed 3.6V when the device is
unpowered.”
Table 4.2, "Electrical
Specifications"
Rev. 1.34 (12-02-08)
DS20005273A-page 46
Added leakage current
Initial document creation
 2014 Microchip Technology Inc.
Multiple Channel 1°C Temperature Sensor with Beta Compensation
Data Sheet
Note the following details of the code protection feature on Microchip devices:
•
Microchip products meet the specification contained in their particular Microchip Data Sheet.
•
Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the
intended manner and under normal conditions.
•
There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our
knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data
Sheets. Most likely, the person doing so is engaged in theft of intellectual property.
•
Microchip is willing to work with the customer who is concerned about the integrity of their code.
•
Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not
mean that we are guaranteeing the product as “unbreakable.”
Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our
products. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts
allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.
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Trademarks
The Microchip name and logo, the Microchip logo, dsPIC, FlashFlex, KEELOQ, KEELOQ logo, MPLAB, PIC, PICmicro, PICSTART, PIC32
logo, rfPIC, SST, SST Logo, SuperFlash and UNI/O are registered trademarks of Microchip Technology Incorporated in the U.S.A. and
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MPF, MPLAB Certified logo, MPLIB, MPLINK, mTouch, Omniscient Code Generation, PICC, PICC-18, PICDEM, PICDEM.net, PICkit,
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SQTP is a service mark of Microchip Technology Incorporated in the U.S.A.
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A more complete list of registered trademarks and common law trademarks owned by Standard Microsystems Corporation (“SMSC”)
is available at: www.smsc.com. The absence of a trademark (name, logo, etc.) from the list does not constitute a waiver of any
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All other trademarks mentioned herein are property of their respective companies.
© 2014, Microchip Technology Incorporated, Printed in the U.S.A., All Rights Reserved.
ISBN: 9781620779521
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and manufacture of development systems is ISO 9001:2000 certified.
 2014 Microchip Technology Inc.
DS20005273A-page 47
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10/28/13
 2014 Microchip Technology Inc.
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