EMC1182 Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications PRODUCT FEATURES Datasheet General Description Applications The EMC1182 is a high accuracy, low cost, 1.8V System Management Bus (SMBus) compatible temperature sensor. Advanced features such as Resistance Error Correction (REC), Beta Compensation (to support CPU diodes requiring the BJT/transistor model including 65nm and lower geometry processors) and automatic diode type detection combine to provide a robust solution for complex environmental monitoring applications. The ability to communicate at 1.8V SMBus levels provides compatible I/O for the advanced processors found in today’s tablet and smartphone applications. Notebook Computers Desktop Computers Industrial Embedded applications Features Support for diodes requiring the BJT/transistor model — Supports 65nm and lower geometry CPU thermal diodes The EMC1182 monitors two temperature channels (one external and one internal), providing ±1°C accuracy for both external and internal diode temperatures. REC automatically eliminates the temperature error caused by series resistance allowing greater flexibility in routing thermal diodes. Frequency hopping* and analog filters ensure remote diode traces can be as far as eight (8) inches without degrading the signal. Beta Compensation eliminates temperature errors caused by low, variable beta transistors common in today's fine geometry processors. The automatic beta detection feature monitors the external diode/transistor and determines the optimum sensor settings for accurate temperature measurements regardless of processor technology. This frees the user from providing unique sensor configurations for each temperature monitoring application. These advanced features plus ±1°C measurement accuracy provide a low-cost, highly flexible and accurate solution for critical temperature monitoring applications. Pin and register compatible with EMC1412 Automatically determines external diode type and optimal settings Resistance Error Correction Frequency hops the remote sample frequency to reject DC converter and other coherent noise sources* Consecutive Alert queue to further reduce false Alerts Up to 1 External Temperature Monitor — 25°C typ, ±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 3.3V Supply Voltage 1.8V SMBus operation Programmable temperature limits for ALERT/THERM2 (85°C default high limit and 0°C default low limit) and THERM (85°C default) Available in small 8-pin 2mm x 3mm TDFN RoHS compliant package Available in small 8-pin 3mm x 3mm DFN RoHS compliant package VDD = 3.3V 1.8V 1.8V – 3.3V VDD VDD EMC1182 DP Internal Temp Diode ALERT / THERM2 Interupt Masking THERM / ADDR SMBus Address Decode External Temperature Register(s) Internal Temperature Register High Limit Registers THERM Limit Register THERM Hysteresis Register SMBus Interface ΔΣADC Digital Mux Analog Mux Digital Mux Low Limit Registers Limit Comparator DP 1 D N1 Host CPU / GPU Conversion Rate Register Switching Current SMCLK Thermal Junction SMCLK DN SMDATA EMC1182 SMDATA SMBus Interface ALERT / THERM2 Configuration Register THERM / ADDR GND Status Registers Power Control GND * Technology covered under the US patent 7,193,543. SMSC EMC1182 Revision 1.0 (07-11-13) DATASHEET Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet Ordering Information: ORDERING NUMBER PACKAGE FEATURES SMBUS ADDRESS EMC1182-A-AC3-TR 8-pin TDFN 2mm x 3mm (RoHS compliant) Two temperature sensors, ALERT/THERM2 and THERM pins, fixed SMBus address Selectable via THERM pull-up EMC1182-1-AIA-TR 8-pin DFN 3mm x 3mm (RoHS compliant) Two temperature sensors, ALERT/THERM2 and THERM pins, fixed SMBus address 1001_100(r/w) EMC1182-1-AC3-TR 8-pin TDFN 2mm x 3mm (RoHS compliant) Two temperature sensors, ALERT/THERM2 and THERM pins, fixed SMBus address 1001_100(r/w) EMC1182-2-AIA-TR 8-pin DFN 3mm x 3mm (RoHS compliant) Two temperature sensors, ALERT/THERM2 and THERM pins, fixed SMBus address 1001_101(r/w) EMC1182-2-AC3-TR 8-pin TDFN 2mm x 3mm (RoHS compliant) Two temperature sensors, ALERT/THERM2 and THERM pins, fixed SMBus address 1001_101(r/w) 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 © 2013 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. The Microchip name and logo, and the Microchip logo are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. 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 1.0 (07-11-13) 2 DATASHEET SMSC EMC1182 Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet Table of Contents Chapter 1 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Chapter 2 Pin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Chapter 3 Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 3.1 Absolute Maximum Ratings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 3.2 Electrical Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 3.3 SMBus Electrical Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Chapter 4 System Management Bus Interface Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 4.1 Communications Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1.1 SMBus Start Bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1.2 SMBus Address and RD / WR Bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1.3 THERM Pin Considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1.5 SMBus Data Bytes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1.6 SMBus ACK and NACK Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1.7 SMBus Stop Bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1.8 SMBus Timeout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1.9 SMBus and I2C Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2 SMBus Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.1 Write Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.2 Read Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.3 Send Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.4 Receive Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3 Alert Response Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 13 13 14 14 14 15 15 15 15 16 16 16 16 17 Chapter 5 Product Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 5.1 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2 Conversion Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3 Dynamic Averaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4 THERM Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4.1 THERM Pin Considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 ALERT / THERM2 Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5.1 ALERT / THERM2 Pin InterruptALERT Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5.2 ALERT / THERM2 Pin ComparatorTHERM Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.6 Temperature Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.6.1 Beta Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.6.2 Resistance Error Correction (REC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.6.3 Programmable External Diode Ideality Factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.7 Diode Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.8 Consecutive Alerts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.9 Digital Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.10 Temperature Measurement Results and Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 19 19 19 20 20 20 20 21 21 21 21 22 22 22 24 Chapter 6 Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 6.1 Data Read Interlock. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 6.2 Temperature Data Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 6.3 Status Register 02h . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 SMSC EMC1182 3 DATASHEET Revision 1.0 (07-11-13) Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet 6.4 Configuration Register 03h / 09h. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.5 Conversion Rate Register 04h / 0Ah . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.6 Limit Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.7 Scratchpad Registers 11h and 12h . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.8 One Shot Register 0Fh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.9 Therm Limit Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.10 Channel Mask Register 1Fh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.11 Consecutive ALERT Register 22h. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.12 Beta Configuration Register 25h . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.13 External Diode Ideality Factor Register 27h . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.14 Filter Control Register 40h. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.15 Product ID Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.16 SMSC ID Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.17 Revision Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 29 30 31 31 32 32 33 34 35 37 37 37 38 Chapter 7 Typical Operating Curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Chapter 8 Package Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 8.1 Package Markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Chapter 9 Datasheet Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Revision 1.0 (07-11-13) 4 DATASHEET SMSC EMC1182 Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet List of Figures Figure 1.1 Figure 2.1 Figure 4.1 Figure 4.4 Figure 5.1 Figure 5.2 Figure 5.3 Figure 5.4 Figure 5.5 Figure 8.1 Figure 8.3 Figure 8.2 Figure 8.4 Figure 8.5 Figure 8.6 Figure 8.7 Figure 8.8 Figure 8.9 Figure 8.10 Figure 8.11 EMC1182 Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 EMC1182 Pin Diagram, TDFN-8 2mm x 3mm / DFN-8 3mm x 3mm . . . . . . . . . . . . . . . . . . . 8 SMBus Timing Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Isolating the THERM pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 System Diagram for EMC1182 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Isolating THERM Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Isolating ALERT and SYS_SHDN Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Temperature Filter Step Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Temperature Filter Impulse Response. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 2mm x 3mm TDFN Package Drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 2mm x 3mm TDFN Package PCB Land Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 2mm x 3mm TDFN Package Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 3mm x 3mm DFN Package Drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 3mm x 3mm DFN Package Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 8 Pin DFN PCB Footprint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 EMC1182-1 8-Pin TDFN Package Markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 EMC1182-2 8-Pin TDFN Package Markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 EMC1182-A 8-Pin TDFN Package Markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 EMC1182-1 8-Pin DFN Package Markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 EMC1182-2 8-Pin DFN Package Markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 SMSC EMC1182 5 DATASHEET Revision 1.0 (07-11-13) Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet List of Tables Table 2.1 EMC1182 Pin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Table 2.2 Pin Types. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Table 3.1 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Table 3.2 Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Table 3.3 SMBus Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Table 4.1 SMBus Address Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Table 4.1 Protocol Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Table 4.2 Write Byte Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Table 4.3 Read Byte Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Table 4.4 Send Byte Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Table 4.5 Receive Byte Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Table 4.6 Alert Response Address Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Table 5.1 Supply Current vs. Conversion Rate for EMC1182 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Table 5.2 Temperature Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Table 6.1 Register Set in Hexadecimal Order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Table 6.2 Temperature Data Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Table 6.3 Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Table 6.4 Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Table 6.5 Conversion Rate Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Table 6.6 Conversion Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Table 6.7 Temperature Limit Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Table 6.8 Scratchpad Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Table 6.9 Therm Limit Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Table 6.10 Channel Mask Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Table 6.11 Consecutive ALERT Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Table 6.12 Consecutive Alert / Therm Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Table 6.13 Beta Configuration Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Table 6.14 Ideality Configuration Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Table 6.15 Ideality Factor Look-Up Table (Diode Model) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Table 6.16 Substrate Diode Ideality Factor Look-Up Table (BJT Model) . . . . . . . . . . . . . . . . . . . . . . . . . 36 Table 6.17 Filter Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Table 6.18 FILTER Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Table 6.19 Product ID Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Table 6.20 Manufacturer ID Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Table 6.21 Revision Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Table 9.1 Customer Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Revision 1.0 (07-11-13) 6 DATASHEET SMSC EMC1182 Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet Chapter 1 Block Diagram VDD EMC1182 Conversion Rate Register Switching Current Low Limit Registers ALERT THERM / ADDR THERM Limit Register THERM Hysteresis Register SMBus Interface Internal Temp Diode External Temperature Register(s) High Limit Registers Digital Mux ΔΣ ADC DN Digital Mux Analog Mux Limit Comparator SMCLK DP SMDATA Internal Temperature Register Interupt Masking Configuration Register SMBus Address Decode Status Registers GND Figure 1.1 EMC1182 Block Diagram SMSC EMC1182 7 DATASHEET Revision 1.0 (07-11-13) Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet Chapter 2 Pin Description EMC1182 VDD 1 8 SMCLK DP 2 7 SMDATA Exposed pad DN 3 6 ALERT / THERM2 THERM / ADDR 4 5 GND Figure 2.1 EMC1182 Pin Diagram, TDFN-8 2mm x 3mm / DFN-8 3mm x 3mm Table 2.1 EMC1182 Pin Description PIN NUMBER NAME 1 VDD 2 DP External diode positive (anode) connection AIO 3 DN External diode negative (cathode) connection AIO 4 FUNCTION Power supply TYPE Power THERM - Active low Critical THERM output signal - requires pull-up resistor OD (5V) ADDR - Selects SMBus address based on pullup resistor OD (5V) THERM / ADDR 5 GND 6 ALERT / THERM2 Active low digital ALERT / THERM2 output signal - requires pull-up resistor OD (5V) 7 SMDATA SMBus Data input/output - requires pull-up resistor DIOD (5V) 8 SMCLK SMBus Clock input - requires pull-up resistor Bottom Pad Exposed Pad Revision 1.0 (07-11-13) Ground Power Not internally connected, but recommend grounding. 8 DATASHEET DI (5V) - SMSC EMC1182 Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet The pin types are described Table 2.2. Table 2.2 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. SMSC EMC1182 9 DATASHEET Revision 1.0 (07-11-13) Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications 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 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 3.1) Voltage on any other pin to Ground Lead Temperature Range Refer to JEDEC Spec. J-STD-020 Package Thermal Characteristics for TDFN-8 Thermal Resistance (θj-a) ESD Rating, All pins HBM 89 °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. Note 3.1 3.2 For the 5V tolerant pins that have a pull-up resistor (SMCLK, SMDATA, THERM, and ALERT / THERM2), the pull-up voltage must not exceed 3.6V when the device is unpowered. 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 Revision 1.0 (07-11-13) 3.0 3.3 3.6 V 200 410 µA 0.0625 conversion / sec, dynamic averaging disabled 215 425 µA 1 conversion / sec, dynamic averaging disabled 10 DATASHEET SMSC EMC1182 Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet Table 3.2 Electrical Specifications (continued) 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 IDD CONDITIONS 325 465 µA 4 conversions / sec, dynamic averaging disabled 890 1050 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 UNITS 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 / THERM2 and THERM pins Output Low Voltage VOL Leakage Current ILEAK SMSC EMC1182 0.4 ±5 11 DATASHEET V ISINK = 8mA µA ALERT / THERM2 and SYS_SHDN pins Device powered or unpowered TA < 85°C pull-up voltage < 3.6V Revision 1.0 (07-11-13) Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet 3.3 SMBus Electrical Characteristics Table 3.3 SMBus Electrical Specifications VDD = 3.0 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 1.4 VDD V 5V Tolerant. Voltage threshold based on 1.8V operation Input Low Voltage VIL -0.3 0.8 V 5V Tolerant. Voltage threshold based on 1.8V operation Leakage Current ILEAK ±5 µA Powered or unpowered TA < 85°C Hysteresis 50 Input Capacitance CIN Output Low Sink Current IOL mV 5 pF 8.2 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 Timeout tTIMEOUT 35 ms Disabled by default Revision 1.0 (07-11-13) 10 25 400 kHz 50 ns 12 DATASHEET SMSC EMC1182 Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet Chapter 4 System Management Bus Interface Protocol 4.1 Communications Protocol The EMC1182 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. . T LOW T HD:STA T HIGH T SU:STO T FALL SMCLK T RISE T HD:STA T HD:DAT T SU:DAT T SU:STA SMDATA TBUF S P S S - Start Condition P - Stop Condition P Figure 4.1 SMBus Timing Diagram 4.1.1 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. 4.1.2 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 EMC1182-A SMBus slave address is determined by the pull-up resistor on the THERM pin as shown in Table 4.1, "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 4.1 SMBus Address Decode SMSC EMC1182 PULL UP RESISTOR ON THERM PIN (±5%) SMBUS ADDRESS 4.7k 1111_100(r/w)b 6.8k 1011_100(r/w)b 13 DATASHEET Revision 1.0 (07-11-13) Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet Table 4.1 SMBus Address Decode (continued) PULL UP RESISTOR ON THERM PIN (±5%) SMBUS ADDRESS 10k 1001_100(r/w)b 15k 1101_100(r/w)b 22k 0011_100(r/w)b 33k 0111_100(r/w)b The EMC1182-1 SMBus address is hard coded to 1001_100(r/w). The EMC1182-2 SMBus address is hard coded to 1001_101(r/w). 4.1.3 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 4.1. 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 4.4, "Isolating the THERM pin". +3.3V +2.5 - 5V 4.7K - 22K 33K VDD 1 DP 2 8 SMCLK 7 SMDATA EMC1182 DN 3 6 ALERT / ADDR THERM 4 5 GND Shared THERM Figure 4.4 Isolating the THERM pin 4.1.5 SMBus Data Bytes All SMBus Data bytes are sent most significant bit first and composed of 8-bits of information. 4.1.6 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. Revision 1.0 (07-11-13) 14 DATASHEET SMSC EMC1182 Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet 4.1.7 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. 4.1.8 SMBus Timeout The EMC1182 supports SMBus Timeout. If the clock line is held low for longer than tTIMEOUT, the device will reset its SMBus protocol. This function can be enabled by setting the TIMEOUT bit (see Section 6.11, "Consecutive ALERT Register 22h"). 4.1.9 SMBus and I2C Compatibility The EMC1182 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 EMC1182 in an I2C system, refer to SMSC AN 14.0 SMSC Dedicated Slave Devices in I2C Systems. 1. EMC1182 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 EMC1182 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 EMC1182 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 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 4.1. Table 4.1 Protocol Format SMSC EMC1182 DATA SENT TO DEVICE DATA SENT TO THE HOST # of bits sent # of bits sent 15 DATASHEET Revision 1.0 (07-11-13) Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet 4.2.1 Write Byte The Write Byte is used to write one byte of data to the registers, as shown in Table 4.2. Table 4.2 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 4.2.2 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 YYYY_ YYY 0 0 XXh 0 1 -> 0 YYYY_ YYY 1 0 XX 1 0 -> 1 4.2.3 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 4.4. Table 4.4 Send Byte Protocol START SLAVE ADDRESS WR ACK REGISTER ADDRESS ACK STOP 1 -> 0 YYYY_YYY 0 0 XXh 0 0 -> 1 4.2.4 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 4.5. Table 4.5 Receive Byte Protocol START SLAVE ADDRESS RD ACK REGISTER DATA NACK STOP 1 -> 0 YYYY_YYY 1 0 XXh 1 0 -> 1 Revision 1.0 (07-11-13) 16 DATASHEET SMSC EMC1182 Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet 4.3 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 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 YYYY_YYY 1 0 -> 1 The EMC1182 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_ALL bit to clear the ALERT pin. APPLICATION NOTE: The ARA does not clear the Status Register and if the MASK_ALL bit is cleared prior to the Status Register being cleared, the ALERT pin will be reasserted. SMSC EMC1182 17 DATASHEET Revision 1.0 (07-11-13) Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet Chapter 5 Product Description The is an SMBus temperature sensor. The EMC1182 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 EMC1182 and using that data to control the speed of one or more fans. The EMC1182 has two levels of monitoring. The first provides a maskable ALERT / THERM2 signal to the host when the measured temperatures exceeds user programmable limits. This allows the EMC1182 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 5.1 shows a system level block diagram of the EMC1182. VDD = 3.3V 1.8V 1.8V – 3.3V VDD CPU / GPU Host DP Thermal Junction DN SMCLK EMC1182 SMDATA ALERT / THERM2 SMBus Interface THERM / ADDR GND Power Control Figure 5.1 System Diagram for EMC1182 5.1 Modes of Operation The EMC1182 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. Revision 1.0 (07-11-13) 18 DATASHEET SMSC EMC1182 Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet 5.2 Conversion Rates The EMC1182 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, "Conversion Rate". 5.3 Dynamic Averaging Dynamic averaging causes the EMC1182 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, "Configuration Register 03h / 09h"). 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. Table 5.1 Supply Current vs. Conversion Rate for EMC1182 AVERAGE SUPPLY CURRENT (TYPICAL) AVERAGING FACTOR (BASED ON 11-BIT OPERATION) CONVERSION RATE ENABLED (DEFAULT) DISABLED ENABLED (DEFAULT) DISABLED 1 / 16 sec 210uA 200uA 16x 1x 1 / 8 sec 265uA 200uA 16x 1x 1 / 4 sec 330uA 200uA 16x 1x 1 / 2 sec 395uA 200uA 16x 1x 1 / sec 460uA 215uA 16x 1x 4 / sec (default) 890uA 325uA 8x 1x 8 / sec 1010uA 630uA 4x 1x 16 / sec 1120uA 775uA 2x 1x 32 / sec 1200uA 1050uA 1x 1x 64 / sec 1400uA 1100uA 0.5x 0.5x 5.4 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). SMSC EMC1182 19 DATASHEET Revision 1.0 (07-11-13) Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications 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. 5.4.1 THERM Pin Considerations Because of the decode method used to determine the SMBus Address, it is important that the pull-up resistance on THERM pin be within ±10% tolerance. 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 the bus during this time. One method of isolating this pin is shown in Figure 5.2. . +3.3V +2.5 - 5V 22 K 4.7K 33 K VDD 1 DP 2 DN THERM / ADDR Shared THERM 3 EMC1182 4 8 SMCLK 7 SMDATA 6 ALERT 5 GND Figure 5.2 Isolating THERM Pin 5.5 ALERT / THERM2 Output The ALERT / THERM2 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 / THERM2 output is selected via the ALERT / COMPALERT/THERM bit in the Configuration Register (see Section 6.4). 5.5.1 ALERT / THERM2 Pin InterruptALERT Mode When configured to operate in interrupt mode, the ALERT / THERM2 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, functioning as any standard ALERT in on the SMBus. The ALERT / THERM2 pin will remain asserted as long as an out-of-limit condition remains. Once the out-of-limit condition has been removed, the ALERT / THERM2 pin will remain asserted until the appropriate status bits are cleared. The ALERT/ THERM2 pin can be masked by setting the MASK_ALL bit. Once the ALERT / THERM2 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 / THERM2 pin is masked will update the Status Register normally. There are also individual channel masks (see Section 6.10). The ALERT / THERM2 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 / THERM2 outputs can be hard-wired together. 5.5.2 ALERT / THERM2 Pin ComparatorTHERM Mode When the ALERT / THERM2 pin is configured to operate in comparator mode, it will be asserted if any of the measured temperatures exceeds the respective high limit, acting as a second THERM function Revision 1.0 (07-11-13) 20 DATASHEET SMSC EMC1182 Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet in. The ALERT / THERM2 pin will remain asserted until all temperatures drop below the corresponding high limit minus the Therm Hysteresis value. When the ALERT / THERM2 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 / THERM2 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 / THERM2 pin in this mode; however, the individual channel masks (see Section 6.10) will prevent the respective channel from asserting the ALERT/ THERM2 pin. 5.6 Temperature Measurement The EMC1182 can monitor the temperature of one externally connected diode. 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. 5.6.1 Beta Compensation The EMC1182 is configured to monitor the temperature of basic diodes (e.g., 2N3904) or CPU thermal diodes. For External Diode 1, 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. 5.6.2 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 EMC1182 automatically corrects up to 100 ohms of series resistance. 5.6.3 Programmable External Diode Ideality Factor The EMC1182 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 EMC1182 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. SMSC EMC1182 21 DATASHEET Revision 1.0 (07-11-13) Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet 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 EMC1182 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 / THERM2 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 / THERM2 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. 5.8 Consecutive Alerts The EMC1182 contains multiple consecutive alert counters. One set of counters applies to the ALERT / THERM2 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 / THERM2 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, "Consecutive ALERT Register 22h" 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 (default) (see Section 6.14). The typical filter performance is shown in Figure 5.4 and Figure 5.5. Revision 1.0 (07-11-13) 22 DATASHEET SMSC EMC1182 Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications 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 5.4 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 5.5 Temperature Filter Impulse Response SMSC EMC1182 23 DATASHEET Revision 1.0 (07-11-13) Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet 5.10 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 EMC1182 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. 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 -1 000 0000 0000 001 1111 1000 0 000 0000 0000 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 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 Revision 1.0 (07-11-13) 24 DATASHEET SMSC EMC1182 Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications 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 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 28 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) 00h (0°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) 09h R/W Configuration Controls the general operation of the device (mirrored at address 03h) 0Ah R/W Conversion Rate Controls the conversion rate for updating temperature data (mirrored at address 04h) SMSC EMC1182 25 DATASHEET 00h 06h (4/sec) Page 28 Page 29 Revision 1.0 (07-11-13) Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet Table 6.1 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 31 12h R/W Scratchpad Scratchpad register for software compatibility 00h Page 31 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 32 1Fh R/W Channel Mask Register Controls the masking of individual channels 00h Page 32 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 33 25h R/W External Diode1 Beta Configuration Stores the Beta Compensation circuitry settings for External Diode1 08h Page 35 27h R/W External Diode Ideality Factor Stores the ideality factor for the External Diode 12h (1.008) Page 35 Page 30 Page 32 Revision 1.0 (07-11-13) 26 DATASHEET SMSC EMC1182 Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet Table 6.1 Register Set in Hexadecimal Order (continued) REGISTER ADDRESS R/W REGISTER NAME FUNCTION DEFAULT VALUE PAGE 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 37 FDh R Product ID Stores a fixed value that identifies the device 20h Page 37 FEh R Manufacturer ID Stores a fixed value that represents SMSC 5Dh Page 37 FFh R Revision Stores a fixed value that represents the revision number 07h Page 38 6.1 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. SMSC EMC1182 27 DATASHEET Revision 1.0 (07-11-13) Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet 6.3 Status Register 02h 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 channels. When any of the bits are set (excluding the BUSY bit) either the ALERT / THERM2 or THERM pin is being asserted. The ALERT / THERM2 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 ETHERM and ITHERM) will remain set until read unless the ALERT pin is configured as a second THERM output (see Section 5.4). Bit 7 - BUSY - This bit indicates that the ADC is currently converting. This bit does not cause either the ALERT / THERM2 or THERM pin 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 / THERM2 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 / THERM2 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 / THERM2 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 / THERM2 pin. Bit 2 - FAULT - This bit is asserted when a diode fault is detected. When set, this bit will assert the ALERT / THERM2 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 03h / 09h Table 6.4 Configuration Register ADDR R/W REGISTER B7 B6 R/W Configuration MASK_ ALL RUN/ STOP 03h 09h B5 B4 B3 B2 B1 B0 DEFAULT ALERT/ THERM2 RECD - RANGE DAVG_ DIS - 00h The Configuration Register controls the basic operation of the device. This register is fully accessible at either address. Revision 1.0 (07-11-13) 28 DATASHEET SMSC EMC1182 Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet Bit 7 - MASK_ALL - Masks the ALERT / THERM2 pin from asserting. ‘0’ - (default) - The ALERT / THERM2 pin is not masked. If any of the appropriate status bits are set the ALERT / THERM2 pin will be asserted. ‘1’ - The ALERT/ THERM2 pin is masked. It will not be asserted for any interrupt condition unless it is configured in comparator mode. The Status Registers 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/THERM2 - Controls the operation of the ALERT / THERM2 pin. ‘0’ (default) - The ALERT / THERM2 acts as an Alert pin and has interrupt behavior as described in Section 5.5.1. ‘1’ - The ALERT / THERM2 acts as a THERM pin and has comparator behavior as described in Section 5.5.2. 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. 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 6.6. ‘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 6.6. Conversion Rate Register 04h / 0Ah Table 6.5 Conversion Rate Register ADDR R/W REGISTER B7 B6 B5 B4 R/W Conversion Rate - - - - 04h 0Ah B3 B2 B1 CONV[3:0] B0 DEFAULT 06h (4/sec) 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. SMSC EMC1182 29 DATASHEET Revision 1.0 (07-11-13) Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet Table 6.6 Conversion Rate CONV[3:0] HEX 3 2 1 0 CONVERSIONS / SECOND 0h 0 0 0 0 / 16 1h 0 0 0 1 1/8 2h 0 0 1 0 1/4 3h 0 0 1 1 1 / 21 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 6.6 All others 1 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 05h 0Bh 06h 0Ch 07h 0Dh 13h Revision 1.0 (07-11-13) 30 DATASHEET SMSC EMC1182 Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet Table 6.7 Temperature Limit Registers (continued) ADDR. R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT 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 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 / THERM2 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 / THERM2 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 (see Section 6.8, "One Shot Register 0Fh") or by clearing the RUN / STOP bit (see Section 6.4, "Configuration Register 03h / 09h"). 6.7 Scratchpad Registers 11h and 12h 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. 6.8 One Shot Register 0Fh 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. SMSC EMC1182 31 DATASHEET Revision 1.0 (07-11-13) Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet 6.9 Therm Limit Registers Table 6.9 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 / THERM2 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 1Fh Table 6.10 Channel Mask Register ADDR. R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT 1Fh R/W Channel Mask - - - - - - EXT MASK INT MASK 00h The Channel Mask Register controls individual channel masking. When a channel is masked, the ALERT / THERM2 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 - EXTMASK - Masks the ALERT / THERM2 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 / THERM2 pin to be asserted if it is out of limit or reports a diode fault. ‘1’ - The External Diode channel will not cause the ALERT / THERM2 pin to be asserted if it is out of limit or reports a diode fault. Bit 0 - INTMASK - Masks the ALERT / THERM2 pin from asserting when the Internal Diode temperature is out of limit. ‘0’ (default) - The Internal Diode channel will cause the ALERT / THERM2 pin to be asserted if it is out of limit. ‘1’ - The Internal Diode channel will not cause the ALERT / THERM2 pin to be asserted if it is out of limit. Revision 1.0 (07-11-13) 32 DATASHEET SMSC EMC1182 Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet 6.11 Consecutive ALERT Register 22h Table 6.11 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 / THERM2 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 / THERM2 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 / THERM2 pin will be asserted, the consecutive alert counter will be cleared, and measurements will continue. When the ALERT / THERM2 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/ THERM2 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 EMC1182 device, the high limits are set at 70°C, and none of the channels are masked, the ALERT / THERM2 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 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 / THERM2 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. ‘1’ - The SMBus Timeout feature is enabled. If the SMCLK line is held low for more than tTIMEOUT, 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 and Hardware Thermal Shutdown Limit before the SYS_SHDN pin is asserted. All temperature channels use this value to set the respective counters. The consecutive THERM counter is incremented whenever any of the measurements exceed the corresponding Therm Limit or if the External Diode measurement exceeds the Hardware Thermal Shutdown Limit. SMSC EMC1182 33 DATASHEET Revision 1.0 (07-11-13) Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet If the temperature drops below the Therm Limit or Hardware Thermal Shutdown Limit, the counter is reset. If the programmed number of consecutive measurements exceed the Therm Limit or Hardware Thermal Shutdown Limit, and the appropriate channel is linked to the SYS_SHDN pin, the SYS_SHDN pin will be asserted low. Once the SYS_SHDN pin is asserted, the consecutive Therm counter will not reset until the corresponding temperature drops below the appropriate limit minus the corresponding hysteresis. 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 6.12. 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 / THERM2 pin is asserted. Both temperature channels use this value to set the respective counters. The bits are decoded as shown in Table 6.12. The default setting is 1 consecutive out of limit conversion. Table 6.12 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 Register 25h Table 6.13 Beta Configuration Register ADDR. R/W REGISTER B7 B6 B5 B4 B3 25h R/W External Diode Beta Configuration - - - - ENABLE B2 B1 BETA[2:0] B0 DEFAULT 08h This register is used to set the Beta Compensation factor that is used for the external diode channel. ‘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. Revision 1.0 (07-11-13) 34 DATASHEET SMSC EMC1182 Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet 6.13 External Diode Ideality Factor Register 27h Table 6.14 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 6.15 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 6.15 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 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 6.16 when using a CPU substrate transistor. SMSC EMC1182 35 DATASHEET Revision 1.0 (07-11-13) Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet Table 6.16 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 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. Bit 1 - E1HIGH - This bit is set when the External Diode 1 channel exceeds its programmed high limit. Bit 0 - IHIGH - This bit is set when the Internal Diode channel exceeds its programmed high limit. Bit 1 - ELOW - This bit is set when the External Diode channel drops below its programmed low limit. Bit 0 - ILOW - This bit is set when the Internal Diode channel drops below its programmed low limit. Bit 1 - ETHERM - This bit is set when the External Diode channel exceeds its programmed Therm Limit. When set, this bit will assert the THERM pin. Bit 0- ITHERM - This bit is set when the Internal Diode channel exceeds its programmed Therm Limit. When set, this bit will assert the THERM pin. Revision 1.0 (07-11-13) 36 DATASHEET SMSC EMC1182 Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet 6.14 Filter Control Register 40h Table 6.17 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 6.18. See Figure 5.4 and Figure 5.5 for examples on the filter behavior. Table 6.18 FILTER Decode 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 6.19 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. 6.16 SMSC ID Register Table 6.20 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 EMC1182. SMSC EMC1182 37 DATASHEET Revision 1.0 (07-11-13) Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet 6.17 Revision Register Table 6.21 Revision Register ADDR. R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT FFh R Revision 0 0 0 0 0 1 1 1 07h The Revision register contains an 8-bit word that identifies the die revision. Revision 1.0 (07-11-13) 38 DATASHEET SMSC EMC1182 Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications 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) Temperature Error (°C) Temperature Error (°C) SMSC EMC1182 5 4 Beta Compensation Disabled 3 2 1 0 Beta Compensation Enabled -1 20 110 125 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) 40 60 80 100 120 CPU Temperature (°C) 39 DATASHEET Revision 1.0 (07-11-13) Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet Chapter 8 Package Information Figure 8.1 2mm x 3mm TDFN Package Drawing Revision 1.0 (07-11-13) 40 DATASHEET SMSC EMC1182 Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet Figure 8.2 2mm x 3mm TDFN Package Dimensions Figure 8.3 2mm x 3mm TDFN Package PCB Land Pattern SMSC EMC1182 41 DATASHEET Revision 1.0 (07-11-13) Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet Figure 8.4 3mm x 3mm DFN Package Drawing Revision 1.0 (07-11-13) 42 DATASHEET SMSC EMC1182 Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet Figure 8.5 3mm x 3mm DFN Package Dimensions SMSC EMC1182 43 DATASHEET Revision 1.0 (07-11-13) Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet Figure 8.6 8 Pin DFN PCB Footprint Revision 1.0 (07-11-13) 44 DATASHEET SMSC EMC1182 Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet 8.1 Package Markings The EMC1182 devices will be marked as shown in Figure 8.7, Figure 8.8., Figure 8.9, Figure 8.10 and Figure 8.11. TOP LINE 1: Preface, First digit of Device Code E 3 LINE 2: Second digit of Device Code, Revision C R PIN 1 BOTTOM BOTTOM MARKING IS NOT ALLOWED Figure 8.7 EMC1182-1 8-Pin TDFN Package Markings TOP LINE 1: Preface, First digit of Device Code E 3 LINE 2: Second digit of Device Code, Revision D R PIN 1 BOTTOM BOTTOM MARKING IS NOT ALLOWED Figure 8.8 EMC1182-2 8-Pin TDFN Package Markings SMSC EMC1182 45 DATASHEET Revision 1.0 (07-11-13) Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet TOP LINE 1: Preface, First digit of Device Code E 3 LINE 2: Second digit of Device Code, Revision A R PIN 1 BOTTOM BOTTOM MARKING IS NOT ALLOWED Figure 8.9 EMC1182-A 8-Pin TDFN Package Markings TOP LINE 1: Device Code, First two digits of 6 digits of lot number 4 4 L L LINE 2: Last 4 digits of lot number L L L L PIN 1 BOTTOM BOTTOM MARKING IS NOT ALLOWED Figure 8.10 EMC1182-1 8-Pin DFN Package Markings Revision 1.0 (07-11-13) 46 DATASHEET SMSC EMC1182 Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet TOP LINE 1: Device Code, First two digits of 6 digits of lot number 4 4 L L LINE 2: Last 4 digits of lot number L L L L PIN 1 BOTTOM BOTTOM MARKING IS NOT ALLOWED Figure 8.11 EMC1182-2 8-Pin DFN Package Markings SMSC EMC1182 47 DATASHEET Revision 1.0 (07-11-13) Dual Channel 1°C Temperature Sensor with Beta Compensation and 1.8V SMBus Communications Datasheet Chapter 9 Datasheet Revision History Table 9.1 Customer Revision History REVISION LEVEL & DATE Rev. 1.0 (07-11-13) Revision 1.0 (07-11-13) SECTION/FIGURE/ENTRY CORRECTION Formal document release 48 DATASHEET SMSC EMC1182