SMSC EMC2101
Revision 2.54 (06-16-09)
DATASHEET
Datasheet
PRODUCT FEATURES
EMC2101
SMBus Fan Control
with 1°C Accurate
Temperature Monitoring
General Description
The EMC2101 is an SMBus 2.0 compliant, integrated
fan control solution complete with two temperature
monitors, one external and one internal. Each
temperature channel has programmable high limits that
can assert an interrupt.
The fan drive is selectable as a Pulse Width Modulator
(PWM) or Linear (DAC) output. The fan control output,
whether the PWM or DAC drive circuit, uses an eight
position look-up table to allow the user to program the
fan speed profile based on temperature. The DAC out-
put ranges from 0V to V
DD
with up to 6 bit resolution
while the PWM output has a range of 0% to 100% with
up to 64 steps.
The EMC2101 has an option to automatically upload the
contents of an attached SMBus compatible EEPROM for
auto-programming upon power up.
Advanced thermal sensing enables reduced validation
and characterization time as well as accurately operat-
ing with smaller-geometry processors. Resistance Error
Correction (REC) automatically corrects the offset errors
of board trace and device resistance, up to 100
Ω. Auto-
matic Beta Compensation allows the user the flexibility
to design applications that include processor substrate
transistors.
Features
Automatic Beta Compensation
Resistance Error Correction
Self-programming with available SMBus compatible
EEPROM
Selectable PWM or DAC fan driver output
Temperature Monitors
— External channel ±1°C accuracy
— Internal channel ±2°C accuracy
3.3 Volt Operation (5 Volt Tolerant Input Buffers)
SMBus 2.0 Compliant Interface, supports TIMEOUT
8-Pin MSOP Lead-free RoHS Compliant Packages
8-Pin SOIC Lead-free RoHS Compliant Package
Applications
Graphics Processors
Embedded Application Fan Drive
PWM Controller + Temp Sensor
Block Diagram
Internal
Temp Diode
Switching
Current
Analog
Mux
Internal
Temperature
Register
Internal High Limit Register
External High Limit Register
Address Pointer Register
Conversion Rate Register
Interupt Masking
Status Registers
Configuration Register
SM
Bu
s I
nter
fa
ce
ALERT / TACH
SMCLK
SMDATA
DP
DN
V
DD
GND
EMC2101
External
Temperature
Register
ΔΣ ADC
FAN
PWM Driver
Fan Control
Logic
External TCRIT Limit Register
Li
mi
t C
o
mp
ar
at
or
DAC Driver
Fan Control
Look-Up Table
ORDER NUMBERS:
EMC2101-ACZL-TR FOR 8-PIN, MSOP LEAD-FREE ROHS COMPLIANT PACKAGE
EMC2101-R-ACZL-TR FOR 8-PIN, MSOP LEAD-FREE ROHS COMPLIANT PACKAGE
EMC2101-ACZT-TR FOR 8-PIN, SOIC LEAD-FREE ROHS COMPLIANT PACKAGE
REEL SIZE IS 4,000 PIECES
SMBus Fan Control with 1°C Accurate Temperature Monitoring
Datasheet
Revision 2.54 (06-16-09)
2
SMSC EMC2101
DATASHEET
80 ARKAY DRIVE, HAUPPAUGE, NY 11788 (631) 435-6000, FAX (631) 273-3123
Copyright © 2009 SMSC or its subsidiaries. All rights reserved.
Circuit diagrams and other information relating to SMSC products are included as a means of illustrating typical applications. Consequently, complete information sufficient for
construction purposes is not necessarily given. Although the information has been checked and is believed to be accurate, no responsibility is assumed for inaccuracies. SMSC
reserves the right to make changes to specifications and product descriptions at any time without notice. Contact your local SMSC sales office to obtain the latest specifications
before placing your product order. The provision of this information does not convey to the purchaser of the described semiconductor devices any licenses under any patent
rights or other intellectual property rights of SMSC or others. All sales are expressly conditional on your agreement to the terms and conditions of the most recently dated
version of SMSC's standard Terms of Sale Agreement dated before the date of your order (the "Terms of Sale Agreement"). The product may contain design defects or errors
known as anomalies which may cause the product's functions to deviate from published specifications. Anomaly sheets are available upon request. SMSC products are not
designed, intended, authorized or warranted for use in any life support or other application where product failure could cause or contribute to personal injury or severe property
damage. Any and all such uses without prior written approval of an Officer of SMSC and further testing and/or modification will be fully at the risk of the customer. Copies of
this document or other SMSC literature, as well as the Terms of Sale Agreement, may be obtained by visiting SMSC’s website at http://www.smsc.com. SMSC is a registered
trademark of Standard Microsystems Corporation (“SMSC”). Product names and company names are the trademarks of their respective holders.
SMSC DISCLAIMS AND EXCLUDES ANY AND ALL WARRANTIES, INCLUDING WITHOUT LIMITATION ANY AND ALL IMPLIED WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE, TITLE, AND AGAINST INFRINGEMENT AND THE LIKE, AND ANY AND ALL WARRANTIES ARISING FROM ANY COURSE
OF DEALING OR USAGE OF TRADE. IN NO EVENT SHALL SMSC BE LIABLE FOR ANY DIRECT, INCIDENTAL, INDIRECT, SPECIAL, PUNITIVE, OR CONSEQUENTIAL
DAMAGES; OR FOR LOST DATA, PROFITS, SAVINGS OR REVENUES OF ANY KIND; REGARDLESS OF THE FORM OF ACTION, WHETHER BASED ON CONTRACT;
TORT; NEGLIGENCE OF SMSC OR OTHERS; STRICT LIABILITY; BREACH OF WARRANTY; OR OTHERWISE; WHETHER OR NOT ANY REMEDY OF BUYER IS HELD
TO HAVE FAILED OF ITS ESSENTIAL PURPOSE, AND WHETHER OR NOT SMSC HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
SMBus Fan Control with 1°C Accurate Temperature Monitoring
Datasheet
SMSC EMC2101
3
Revision 2.54 (06-16-09)
DATASHEET
Table of Contents
Chapter 1 Device Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Chapter 2 Pin Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.1
Pin Diagram for EMC2101 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.2
Pin Description for EMC2101 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Chapter 3 Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.1
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.2
Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.3
SMBus Client Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.4
EEPROM Loader Electrical Specifications (EMC2101-R only) . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Chapter 4 System Management Bus Interface Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.1
System Management Bus Interface Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.2
Write Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.3
Read Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.4
Send Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.5
Receive Byte. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.6
Alert Response Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.7
SMBus Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.8
SMBus Time-out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.9
Programming from EEPROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Chapter 5 General Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.1
Modes of Operation (EMC2101-R Only). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.2
Power Up (EMC2101-R Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.3
Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.4
ALERT / TACH Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
5.4.1
ALERT / TACH as a Temperature Comparator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
5.4.2
ALERT / TACH as an Interrupt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
5.4.3
Mask Bit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
5.5
Temperature Monitors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
5.5.1
Temperature Measurement Results and Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
5.5.2
Temperature Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
5.5.3
Beta Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
5.5.4
Resistance Error Correction (REC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
5.5.5
Programmable Ideality Factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
5.5.6
Diode Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
5.6
Fan Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
5.6.1
DAC Driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
5.6.2
PWM Driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
5.6.3
TACH Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
5.6.4
Fan Control Look-Up Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Chapter 6 Register Set. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
6.1
Data Read Interlock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
6.2
Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
6.3
Temperature Data Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
6.4
Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
6.5
Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
6.6
Conversion Rate Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
SMBus Fan Control with 1°C Accurate Temperature Monitoring
Datasheet
Revision 2.54 (06-16-09)
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SMSC EMC2101
DATASHEET
6.7
Temperature Limit Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
6.8
External Temperature Force Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
6.9
One Shot Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
6.10 Scratchpad Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
6.11 Alert Mask Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
6.12 External Ideality Factor Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
6.13 Beta Compensation Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
6.14 TACH Reading Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
6.15 TACH Limit Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
6.16 Fan Configuration Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
6.17 Fan Spin Up Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
6.18 Fan Setting Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
6.19 PWM Frequency Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
6.20 PWM Frequency Divide Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
6.21 Fan Control Look-Up Table Hysteresis Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
6.22 Fan Control Look-Up Table Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
6.23 Averaging Filter Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
6.24 Product ID Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
6.25 Manufacturer ID Register (FEh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
6.26 Revision Register (FFh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Chapter 7 Package Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Appendix A Advanced PWM Options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Appendix B TACH Reference Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Revision History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
SMBus Fan Control with 1°C Accurate Temperature Monitoring
Datasheet
SMSC EMC2101
5
Revision 2.54 (06-16-09)
DATASHEET
List of Figures
Figure 2.1 EMC2101 Pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Figure 4.1 SMBus Timing Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Figure 5.1 System Diagram for EMC2101 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Figure 5.2 System Diagram for EMC2101-R. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Figure 5.3 Block Diagram of Temperature Monitoring Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Figure 5.4 External Diode configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Figure 5.5 Temperature Filter Step Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Figure 5.6 Temperature Filter Impulse Response. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Figure 5.7 Fan Control Look-Up Table Example. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Figure 5.8 Example Fault Queue Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Figure 9.1 8-PIN MSOP / TSSOP Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Figure 9.2 8-PIN SOIC Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
SMBus Fan Control with 1°C Accurate Temperature Monitoring
Datasheet
Revision 2.54 (06-16-09)
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SMSC EMC2101
DATASHEET
List of Tables
Table 1.1 Device Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Table 2.1 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 3.4 EEPROM Loader Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Table 4.1 Protocol Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Table 4.2 Write Byte Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Table 4.7 Block Read Byte Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Table 5.1 ALERT/ TACH Pull-up Resistors - SMBus / FAN MODE for EMC2101-R . . . . . . . . . . . . . . . 21
Table 5.2 EMC2101 External Temperature Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Table 5.3 EMC2101 Internal Temperature Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Table 6.1 Register Set in Hexadecimal Order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Table 6.2 Temperature Data Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Table 6.3 Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Table 6.4 Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Table 6.5 Conversion Rate Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Table 6.6 Conversion Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Table 6.7 Temperature Data Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Table 6.8 External Diode Force Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Table 6.9 One Shot Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Table 6.10 Scratchpad Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Table 6.11 Alert Mask Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Table 6.12 External Ideality Factor Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Table 6.13 Ideality Factor Look-Up Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Table 6.14 Beta Compensation Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Table 6.15 CPU Beta Values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Table 6.16 TACH Reading Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Table 6.17 TACH Reading Low Byte Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Table 6.18 Fan Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Table 6.19 TACH Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Table 6.20 Fan Spin Up Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Table 6.21 Spin-Up Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Table 6.22 Spin-Up Time. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Table 6.23 Fan Setting Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Table 6.24 PWM Frequency Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Table 6.25 PWM Frequency Divide Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Table 6.26 Examples of Fan PWM Frequency with Maximum Resolution . . . . . . . . . . . . . . . . . . . . . . . . 45
Table 6.27 Look Up Table Hysteresis Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Table 6.28 Fan Control Look Up Table Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Table 6.29 Averaging Filter Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Table 6.30 Averaging Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Table 6.31 Product ID Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Table 6.32 Manufacturer ID Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Table 6.33 Revision Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Customer Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
SMBus Fan Control with 1°C Accurate Temperature Monitoring
Datasheet
SMSC EMC2101
7
Revision 2.54 (06-16-09)
DATASHEET
Chapter 1 Device Selection
The EMC2101 is available with the following options and configurations as shown in
Table 1.1
.
Table 1.1 Device Selection
PART NUMBER
FAN OPERATION
COMMUNICATIONS
PACKAGE
PRODUCT ID
EMC2101
PWM Drive, 0% drive
SMBus
8 pin SOIC and
8 pin MSOP
16h
EMC2101-R
Selected via pull-up
Selected via pull-up
8 pin MSOP
28h
SMBus Fan Control with 1°C Accurate Temperature Monitoring
Datasheet
Revision 2.54 (06-16-09)
8
SMSC EMC2101
DATASHEET
Chapter 2 Pin Layout
2.1
Pin Diagram for EMC2101
2.2
Pin Description for EMC2101
The pin types are described below. All pins labelled with (5V) are 5V tolerant.
Figure 2.1 EMC2101 Pinout
Table 2.1 Pin Description
PIN NAME
FUNCTION
TYPE
1
VDD
3.3V Power supply
Power
2
DP
External diode positive (anode)
connection
AI
3
DN
External diode negative (cathode)
connection
AI
4
FAN
PWM Output
(default - software programmed)
OD (5V)
DAC Output
software programmed
AO
5
GND
Ground
Power
6
ALERT / TACH
ALERT - Open drain I/O operates as
active low interrupt or TACH input -
requires pull-up resistor, which defines
auto-configuration mode (see
Table 5.1
)
OD (5V)
TACH - TACH input
DI (5V)
7
SMDATA
SMBus Data input/output
DIOD Output (5V)
8
SMCLK
SMBus Clock input
DIOD Output (5V)
SMDATA
SMCLK
ALERT / TACH
VDD
DP
DN
FAN
GND
EMC2101
1
2
3
4
5
8
7
6
SMBus Fan Control with 1°C Accurate Temperature Monitoring
Datasheet
SMSC EMC2101
9
Revision 2.54 (06-16-09)
DATASHEET
APPLICATION NOTE: For the 5V tolerant pins that have a pull-up resistor, the voltage difference between VDD and
the pull-up voltage must never exceed 3.6V.
Table 2.2 Pin Types
PIN TYPE
DESCRIPTION
Power
This pin is used to supply power or ground to the device.
DI
Digital Input - this pin is used as a digital input. This pin is
5V tolerant.
AI
Analog Input - this pin is used as an input for analog
signals.
AO
Analog Output - this pin is used as an output for analog
signals.
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.
SMBus Fan Control with 1°C Accurate Temperature Monitoring
Datasheet
Revision 2.54 (06-16-09)
10
SMSC EMC2101
DATASHEET
Chapter 3 Electrical Specifications
3.1
Absolute Maximum Ratings
Note: Stresses above those listed could cause permanent damage to the device. This is a stress
rating only and functional operation of the device at any other condition above those indicated
in the operation sections of this specification is not implied. When powering this device from
laboratory or system power supplies, it is important that the Absolute Maximum Ratings not be
exceeded or device failure can result. Some power supplies exhibit voltage spikes on their
outputs when the AC power is switched on or off. In addition, voltage transients on the AC
power line may appear on the DC output. If this possibility exists, it is suggested that a clamp
circuit be used.
Note 3.1
For the 5V tolerant pins that have a pull-up resistor, the pull-up voltage must not exceed
3.6V when the EMC2101 is unpowered.
3.2
Electrical Specifications
Table 3.1 Absolute Maximum Ratings
DESCRIPTION
RATING
UNIT
Supply Voltage (V
DD
)
-0.3 to 5.0
V
Voltage on 5V tolerant pins (V
5VT_pin
)
-0.3 to 5.5
V
Voltage on 5V tolerant pins (|V
5VT_pin
- V
DD
|) (see
Note 3.1
)
-0.3 to 3.6
V
Voltage on any other pin to Ground
-0.3 to V
DD
+0.3
V
Operating Temperature Range
-40 to 125
°C
Storage Temperature Range
-55 to 150
°C
Lead Temperature Range
Refer to JEDEC Spec. J-STD-
020
Package Thermal Characteristics for MSOP-8
Thermal Resistance
140.8
°C/W
Package Thermal Characteristics for SOIC-8
Thermal Resistance
135.9
°C/W
ESD Rating, All pins HBM
2000
V
Table 3.2 Electrical Specifications
V
DD
= 3.0V to 3.6V, T
A
= 0
o
C - 85
o
C, Typical values are at T
A
= 27°C unless otherwise noted
CHARACTERISTIC
SYMBOL
MIN
TYP
MAX
UNIT
CONDITIONS
DC Power
Supply Voltage
V
DD
3.0
3.3
3.6
V