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EMCT03 1C Triple SMBus Temperature Sensor
Datasheet
General Description
The EMCT03 is a System Management Bus (SMBus) temperature sensor that is capable of monitoring three temperature zones. The three temperature zones consist of two external and one internal temperature diode. The internal 11 bit sigma-delta ADC architecture with digital filtering attributes to superb linearity and immunity to interference and noise. An extended temperature format may be selected for compatibility with a broad range of CPUs. Selectable conversion rates and standby mode support low-power operation.
Features
Low Power; 3.0V to 3.6V Supply
-- Programmable conversion rate -- < 1mA at 16 Conversions per Second -- < 3uA in Standby Mode

SMBus 2.0 Compliant interface Two External Temperature Monitors:
-- -- -- -- Range -64C to +191C 0.125C resolution 1C Accuracy 40C to 80C Diode Fault Reporting
Internal Temperature Monitor
-- Range 0C to +85C -- 0.125C resolution -- 3C Accuracy 0C to 85C

Programmable Conversion Rate MSOP-8 3x3mm Package; Green, Lead-Free Package also available.
Simplified Block Diagram
EMCT03
Switching Current Remote Temp Register 1 SMBus Interface Analog Mux Configuration Register
DP1 DN1
DP2 DN2 Local Temp Diode
11-bit Sigma Delta ADC
Remote Temp Register 2
Digital Mux and Byte Interlock
Local Temp Register Status Register
SMCLK SMDATA
SMSC EMCT03
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1C Triple SMBus Temperature Sensor Datasheet
ORDER NUMBER(S): EMCT03-ACZB for 8-pin MSOP package EMCT03-ACZB-TR for 8-pin MSOP package (Tape and Reel) EMCT03-ACZL for 8-pin MSOP package (Green Lead-Free) EMCT03-ACZL-TR for 8-pin MSOP package (Green Lead-Free, Tape and Reel) Evaluation Board Available upon request.
80 Arkay Drive Hauppauge, NY 11788 (631) 435-6000 FAX (631) 273-3123
Copyright (c) SMSC 2005. 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.
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Chapter 1 Pin Configuration
DP1 DN1 DP2 DN2
1 2 3 4
8
SMCLK SMDATA VDD GND
EMCT03 TOP VIEW
7 6 5
Figure 1.1 EMCT03 Pin Configuration
Table 1.1 Pin Description
PIN DP1 DN1 DP2 DN2 GND VDD SMDATA SMCLK PIN NO. 1 2 3 4 5 6 7 8 DESCRIPTION Positive Analog Input for External Temperature Diode 1 Negative Analog Input for External Temperature Diode 1 Positive Analog Input for External Temperature Diode 2 Negative Analog Input for External Temperature Diode 2 Ground Supply Voltage System Management Bus Data Input/Output, open drain output System Management Bus Clock Input
Table 1.2 Absolute Maximum Ratings
DESCRIPTION Supply Voltage VDD Voltage on any other pin Operating Temperature Range Storage Temperature Range ESD Rating, All Pins Human Body Model RATING -0.3 to 5.0 -0.3 to VDD+0.3 0 to 85 -55 to 150 2000 UNIT V V C C V
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Chapter 2 Electrical Characteristics
VDD=3.3V10%, AmbientTemp=0C to 85C, except as noted below. CHARACTERISTIC DC Power Supply Voltage VDD Current Consumption from VDD: 16 sets of conversions per second 8 sets of conversions per second 4 full sets of conversions per second 2 full sets of conversions per second 1 full set of conversions per second Power Down POR Threshold Internal Temperature Monitor Temperature Accuracy Ambient Temp 0C to 85C Temperature Resolution Two External Temperature Monitors Temperature Accuracy Remote Diode 40C to 80C, Ambient Temp 15C to 70C Remote Diode 0C to 125C Temperature Resolution Current Source Low Level High Level ADC Conversion Time for all three sensors Wake-up from STOP mode (During one shot command or transition to RUN mode) Resolution Differential Non Linearity Integral Non Linearity 11 1 1 60 1 ms ms bit LSB LSB 0.125 10 170 1 3 C C C A A 1 0.125 3 C C 2.5 3.0 3.3 3.6 3 1.75 1 700 500 3 V mA mA mA A A A V MIN TYP MAX UNIT
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TLOW THIGH
THD:STA TF
TSU:STO
SMCLK
THD:STA
TR
THD:DAT TSU:DAT
TSU:STA
SMDATA
TBUF
P
S
S - Start Condition
S
P - Stop Condition
P
Figure 2.1 System Management Bus Timing Diagram
VDD=3.3V10%, Temp=0C to 85C, unless otherwise noted. CHARACTERISTIC System Management Bus Timing Operating Frequency, FSMB Spike Suppression Bus free time Start to Stop, TBUF Hold time Start THD:STA Setup time Start TSU:STA Setup time Stop TSU:STO Data hold time THD:DAT Data setup time TSU:DAT Clock Low period TLOW Clock High Period THIGH Clock/Data Fall Time, TF Clock/Data Rise Time, TR System Management Bus SMCLK, SMDATA Input High Current Input Low Current Input Capacitance Low Input Level High Input Level Hysteresis Low Output Level @ 4mA 2.0 500 0.4 10 -10 10 0.8 A A pF V V mV V 1.3 0.6 0.6 0.6 0.3 100 1.3 0.6 300 300 0.9 10 400 50 kHz ns s s s s s ns s s ns ns MIN TYP MAX UNIT
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Chapter 3 Product Description
The EMCT03 is an SMBus sensor that is capable of monitoring three temperature zones. The part may be used as a companion to one of SMSC's broad line of SIO host circuits, or other devices capable of performing the SMBus host function.
EMCT03
DP1 DN1 DP2 DN2 Internal Diode
Host (SMSC SIO) SMBus SMBus Interface
Figure 3.1 System Overview
In cooperation with the host device, thermal management can be performed as outlined in Figure 3.1 above. Thermal management consists of the host reading the temperature data from the remote and internal temperature diodes of the EMCT03 and controlling the speed of one or multiple fans. Since the EMCT03 incorporates one internal and two external temperature diodes, three separate thermal zones can be monitored and controlled with this application. Also, measured temperature levels can quickly be compared to preset limits within the host device which in turn will take the appropriate action when values are found to be out of limit. The EMCT03 has two basic modes of operation:
Run Mode: In this mode, the EMCT03 continuously converts temperature data and updates its registers. The conversion rate is configured by the lower bits in the configuration register as described in Table 3.11, "Configuration Register, Conversion Rate," on page 11. Standby Mode: In this mode, the EMCT03 is powered down, drawing a maximum current of only 3uA. The SMBus is still operational and a one-shot command can be given which will force the circuit to complete one full set of temperature conversions. The EMCT03 will return to Standby Mode after the one shot conversion has finished.
3.1
Temperature Monitors
Thermal diode temperature measurements are based on the change in forward bias voltage of a diode when operated at two different currents:
Vbe _ high - Vbe _ low = n
where:
KT I high ln q I low
(1)
K is Boltzmann's constant T is Absolute Temperature in Kelvin q is Charge Electron n is Diode Ideality factor The change in forward bias voltage is now proportional to absolute temperature T.
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VDD Ihigh Ilow Ibias fs fs fs fs/2048
Internal or Remote Diode
Bias Diode
Delta Vbe Sample & Hold
1-bit Sigma Delta Modulator
Digital Averaging Filter
11-bit Accurate Conversion
Figure 3.2 Block Diagram of Temperature Measurement Circuit
Figure 3.2 shows a detailed block diagram of the temperature measurement circuit. As shown, the EMCT03 incorporates switched capacitor technology that samples the external remote temperature diode voltage at two bias currents and holds the difference voltage. The sample frequency is 100kHz and the current levels Ihigh and Ilow are 170uA and 10uA respectively. The negative terminal for the remote temperature diode, DN, is internally biased with a forward diode voltage referenced to ground. The output of the switched capacitor sample and hold circuit interfaces to a single-bit sigma delta analog-to-digital converter. This ADC runs at 100kHz sample frequency and its output is digitally filtered and averaged over 2048 samples effectively generating 11 bit accuracy. The advantages of this architecture over Nyquist rate FLASH or SAR converters are superb linearity and inherent noise immunity. The linearity can be directly attributed to the sigma delta ADC single-bit comparator while the noise immunity is achieved by the digital averaging filter. The overall effective bandwidth of the system is fs/2048 which translates to a 50Hz bandwidth at 100kHz sample rate. Conversion time equals about 20ms per temperature monitor which equals 60ms total for three monitors when configured for maximum conversion rate (default). The 11 bit conversion can be displayed in either legacy format or in extended range format. In Legacy format, the temperature range covers -64C to 127C while in extended format, temperature readings span -64C to 191C. It should be noted that the latter range is really meant to cover thermal diodes with a non ideal curvature caused by factor n in equation (1) not being equal to exactly 1.000. In general, it is not recommended to run silicon based thermal diodes at temperatures above 150C.
3.2
System Management Bus Interface Protocol
The EMCT03 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. Detailed timing diagrams can be found in the electrical characteristics of the SMBus. The EMCT03 is SMBus 2.0 compatible and supports Write Byte and Read Byte as valid protocols as shown below:
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3.2.1
Write Byte
The write Byte is used to write one byte of data to the registers as shown in Table 3.1 below:
Table 3.1 SMBus Write Byte Protocol
Start Slave Address WR ACK Register Address ACK Register Data ACK STOP
1
7
1
1
8
1
8
1
1
3.2.2
Read Byte
The Read Byte protocol is used to read one byte of data from the registers as shown in Table 3.2 below:
Table 3.2 SMBus Read Byte Protocol
Start 1 Slave Address 7 WR 1 ACK 1 Register Address 8 ACK 1 START 1 Slave Address 7 RD 1 ACK 1 Register Data 8 NACK 1 STOP 1
3.2.3
SMBus Address
Attempting to communicate with the EMCT03 SMBus interface with an invalid slave address or invalid protocol, results in no response from the part and will not affect its register content. The EMCT03 supports stretching of the SMCLK signal by other devices on the SMBus but will not perform this operation itself.
Table 3.3 SMBus Address
CONDITION EMCT03 Default Address EMCT03 ADDRESS 1001100xb
3.3
Register Allocation
The following registers are accessible through the SMBus:
Table 3.4 Register Table
REGISTER READ ADDRESS 00h 23h 01h 10h F8h F9h REGISTER WRITE ADDRESS N/A N/A N/A N/A N/A N/A DEFAULT VALUE 00h 00h 00h 00h 00h 00h
REGISTER NAME Legacy Format Internal Temperature High Byte Legacy Format Internal Temperature Low Byte Legacy Format Remote Temperature 1 High Byte Legacy Format Remote Temperature 1 Low Byte Legacy Format Remote Temperature 2 High Byte Legacy Format Remote Temperature 2 Low Byte
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Table 3.4 Register Table (continued)
REGISTER READ ADDRESS FAh FBh FCh FDh 02h 03h N/A FEh FFh 11h, 16h, 4Ah, 60h, 61h, 62h, 79h, 7Ah REGISTER WRITE ADDRESS N/A N/A N/A N/A N/A 09h 0Fh N/A N/A 11h, 16h, 4Ah, 60h, 61h, 62h, 79h, 7Ah DEFAULT VALUE 00h 00h 00h 00h 00h 47h -5Dh 01h
REGISTER NAME Extended Format Remote Temperature 1 High Byte Extended Format Remote Temperature 1 Low Byte Extended Format Remote Temperature 2 High Byte Extended Format Remote Temperature 2 Low Byte Status register Configuration register One Shot Command Manufacturer Identifier Silicon Revision Identifier Reserved Registers for production test
During Power on Reset (POR), the default values are stored in the registers. A POR is initiated when power is first applied to the part and the voltage on the VDD supply surpasses the POR level as specified in the electrical characteristics. Any reads to undefined registers will return 00h. Writes to any undefined registers will not have an effect. The EMCT03 uses an interlock mechanism that prevents changes in register content when fresh readings come in from the ADC during successive reads from a host. When the High Byte is read, the last conversion value is latched into the High Byte and Low Byte. Please note that the interlock mechanism is only effective when reading the High Byte first.
3.4
Temperature Monitor Registers
As shown in Table 3.4, each temperature monitor has two byte wide data registers. The external monitors are equipped with both legacy and extended data format. The 11 bit data temperature is stored aligned to the left resulting in the High Byte to contain temperature in 1C steps and the Low Byte to contain fractions of C as outlined below:
Table 3.5 High Byte Temperature Register
REGISTER Temperature High Byte Registers 00h, 01h, F8h, FAh, FCh BIT 7 SIGN BIT 6 64 BIT 5 32 BIT 4 16 BIT 3 8 BIT 2 4 BIT 1 2 BIT 0 1
Table 3.6 Low Byte Temperature Register
REGISTER Temperature Low Byte Registers 23h, 10h, F9h, FBh, FDh BIT 7 0.500 BIT 6 0.250 BIT 5 0.125 BIT 4 0 BIT 3 0 BIT 2 0 BIT 1 0 BIT 0 0
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3.5
Legacy Temperature Data Format Registers 00h, 23h, 01h, 10h, F8h, F9h:
For registers displaying legacy temperature data format, the temperature range spans from -63.875C to +127.875C with 0,125C resolution. Temperatures outside this range are clipped to -63.875C and +127.875C. Data is stored in the registers in 2's complement as shown in Table 3.7:
Table 3.7 Legacy Temperature Data Format
TEMPERATURE (C) Diode Fault = -63.875 -63 -1 0 +0.125 +1 +127 +127.875 2'S COMPLEMENT 1000 0000 0000 0000 1100 0000 0010 0000 1100 0001 0000 0000 1111 1111 0000 0000 0000 0000 0000 0000 0000 0000 0010 0000 0000 0001 0000 0000 0111 1111 0000 0000 0111 1111 1110 0000 HEX 8000 C020 C100 FF00 0000 0020 0100 7F00 7FE0
3.6
Extended Temperature Data Format Registers FAh, FBh, FCh, FDh
For registers displaying extended temperature data format, a value of 64d is subtracted from the Legacy Format output. This effectively extends the range to cover higher external temperature measurements while still maintaining the 2's complement format. Obviously, the host will have to compensate and add 64d to the read temperature data. This format spans from -63.875C to +191.875C with 0.125C resolution. Temperatures outside this range are limited to -63.875C and +191.875C. Table 3.8 shows example temperature readings and register content for this data format.
Table 3.8 Extended Temperature Data Format
ACTUAL TEMP. (C) Diode Fault = -63.875 -63 -1 0 +0.125 +1 +63 +64 -127.875 -127 -65 -64 -63.875 -63 -1 0 -64C OFFSET (C) 2'S COMPLEMENT OF -64C OFFSET 1000 0000 0000 0000 1000 0000 0010 0000 1000 0001 0000 0000 1011 1111 0000 0000 1100 0000 0000 0000 1100 0000 0010 0000 1100 0001 0000 0000 1111 1111 0000 0000 0000 0000 0000 0000 HEX 8000 8020 8100 BF00 C000 C020 C100 FF00 0000
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Table 3.8 Extended Temperature Data Format (continued)
ACTUAL TEMP. (C) +65 +191 = +191.875 -64C OFFSET (C) 1 127 127.875 2'S COMPLEMENT OF -64C OFFSET 0000 0001 0000 0000 0111 1111 0000 0000 0111 1111 1110 0000 HEX 0100 7F00 7FE0
Table 3.7 and Table 3.8 show that temperature data is stored in 2's complement in both Legacy and Extended Temperature Data Format. Both extended and legacy temperature formats are updated simultaneously after every conversion cycle. Code 8000h is reserved for diode fault signaling which occurs when open or short conditions are present between the external DP and DN pins.
3.7
Status Register
Table 3.9 Status Register
REGISTER Status
BIT 7 Busy
BIT 6 -
BIT 5 -
BIT 4 -
BIT 3 -
BIT 2 -
BIT 1 D2
BIT 0 D1
DEF 00h
The Status register is a read only register and returns the operational status of the part. It indicates an external diode fault conditions through bit 0 and 1. When either D1 or D2 is set, a faulty diode connection is detected for external diode 1 or external diode 2 respectively. Also, when diode faults are detected, temperature readings for the faulty external diode will return 8000h. The EMCT03 detects both open and short conditions for the DP1/2 and DN1/2 pins. Bit 7 of the status register will be set when the internal ADC is busy converting data.
3.8
Configuration Register
Table 3.10 Configuration Register
REGISTER BIT 7 BIT 6 nRun/Stop BIT 5 BIT 4 BIT 3 BIT 2 CR2 BIT 1 CR1 BIT 0 CR0 DEF 47h
Configuration
Bits 0 through bit 2 of the configuration register set the ADC conversion rate of the part:
Table 3.11 Configuration Register, Conversion Rate
CR2, CR1, CR0 000 001 010 011 100 101 110 111
SMSC EMCT03
CONVERSION RATE Reserved Reserved Reserved 1 Conversions per second 2 Conversions per second 4 Conversions per second 8 Conversions per second 16 Conversions per second
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A conversion for all 3 temperature readings takes about 60ms. Therefore, the maximum conversion rate, equals 16 conversions per second. Bits 6 set of the Configuration Register sets the power mode of the part:
Table 3.12 Configuration Registers Data Format
NRUN/STOP 0 1 DESCRIPTION Run Mode Standby Mode
In Run Mode, the EMCT03 will operate at the preset conversion rate. In Standby Mode, the part is powered down to minimize current consumption. The SMBus is fully operational in either mode. In Standby Mode, a WRITE command to the One Shot register will trigger a one time conversion of the 3 temperature monitors. After the part finishes the conversion, it will go back to Standby Mode. The host can now read the updated temperature information.
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Chapter 4 Application Information
This chapter provides information on maintaining accuracy when using diodes as remote sensors with SMSC Environmental Monitoring and Control devices. It is assumed that the users have some familiarity with hardware design and transistor characteristics. SMSC supplies a family Environmental Monitoring and Control (EMC) devices that are capable of accurately measuring temperatures. Most devices include an internal temperature sensor along with the ability to measure one or more external sensors. The characteristics of an appropriate diode for use as the external sensor are listed in this chapter. Recommendations for the printed circuit board layout are provided to help reduce error caused by electical noise or trace resistance.
4.1
4.1.1
Maintaining Accuracy
Physical Factors
Temperature measurement is performed by measuring the change in forward bias voltage of a diode when two different currents are forced through the junction. The circuit board itself can impact the ability to accurately measure these small changes in voltage. For example, an excessive amount of series resistance can introduce error in the measurement.
4.1.1.1
Layout
Apply the following guidelines when designing the printed circuit board: 1. Route the remote diode traces on the top layer. 2. Place a ground guard signal on both sides of the differential pair. This guard band should be connected to the ground plane at least every 0.25 inches. 3. Place a ground plane on the layer immediately below the diode traces. 4. Keep the diode traces as short as possible. 5. Keep the diode traces parallel, and the length of the two traces identical within 0.3 inches. 6. Use a trace width of 0.01 inches with a 0.01 inch guard band on each side. 7. Keep the diode traces away from sources of high frequency noise such as power supply filtering or high speed digital signals. 8. When the diode traces must cross high speed digital signals, make them cross at a 90 degree angle. 9. Avoid joints of copper to solder that can introduce thermocouple effects. These recommendations are illustrated in Figure 4.1 Routing the Diode Traces on page 14.
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.01 GAP MIN.
.01 WIDE MIN.
.01 GAP MIN.
.01 WIDE MIN.
.01 GAP MIN.
DP or DN GND PLANE COPPER TRACE BOARD MATERIAL
DP or DN COPPER TRACE GND PLANE
COPPER PLANE (TO SHIELD FROM NOISE)
RECOMMEND VIA STICTCHING AT .25 INCH INTERVALS.
Figure 4.1 Routing the Diode Traces 4.1.1.2 Bypass Capacitors
Accurate temperature measurements require a clean, stable power supply. Locate a 0.1F capacitor as close as possible to the power pin with a good ground. A low ESR capacitor (such as a 10F ceramic) should be placed across the power source. Add additional power supply filtering in systems that have a noisy power supply. A capacitor may be placed across the DP/DN pair at the remote sensor in noisy environments. Do not exceed a value of 100 pF if this capacitor is installed.
4.1.1.3
Manufacturing
Circuit board assembly processes may leave a residue on the board. This residue can result in unexpected leakage currents that may introduce errors if the circuit board is not clean. For example, processes that use water-soluble soldering fluxes have been known to cause problems if the board is not kept clean.
4.1.1.4
Thermal Considerations
Keep the sensor in good thermal contact with the component to be measured. The temperature of the leads of a discrete diode will greatly impact the temperature of the diode junction. Make use of the printed circuit board to disperse any self-heating that may occur.
4.1.1.5
Remote Sensors Connected by Cables
When connecting remote diodes with a cable (instead of traces on the PCB) use shielded twisted pair cable. The shield should be attached to ground near the EMCT03, and should be left unconnected at the sensor end. Belden 8451 cable is a good choice for this application.
4.1.2
Sensor Characteristics
The characteristics of the diode junction used for temperature sensing will affect the accuracy of the measurement.
4.1.2.1
Selecting a Sensor
A diode connected small signal transistor is recommended. Silicon diodes are not a good choice for remote sensors. Small signal transistors such as the 2N3904 or the 2N3906 are recommended. Desired characteristics for the sensor include the following: 1. Constant value of hFE in the range of 7.5 to 130 microamps. Variation in hFE from one device to another or one manufacturer to another cancels out of the temperature equations.
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2. The lowest emitter and base resistance values will also be helpful as a matter of series input resistance
4.1.2.2
Compensating for Ideality of the diode
The remote diode may have an ideality factor based on the manufacturing process. Inaccuracy in the temperature measurement resulting from this ideality factor may be eliminated by calibrating the remote diode with the temperature sensor. The EMCT03 is trimmed to an ideality factor of 1.008.
4.1.2.3
Circuit Connections
The more negative terminal for the remote temperature diode, DN, is internally biased with a forward diode voltage. Terminal DN is not referenced to ground. Remote temperature diodes can be constructed as shown in Figure 4.2 Remote Temperature Diode Examples on page 15.
To DP To DN Local Ground
Typical Remote Parasitic Substrate Transistor e.g. CPU substrate PNP
To DP
To DP
To DN
To DN
Typical Remote Discrete PNP Transistor e.g 2N3906
Typical Remote Discrete NPN Transistor e.g. 2N3904
Figure 4.2 Remote Temperature Diode Examples Environmental Monitoring and Control (EMC) devices supplied by SMSC are designed to make accurate temperature measurements. Careful design of the printed circuit board and proper selection of the remote sensing diode will help to maintain the accuracy.
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Chapter 5 Package Outline
Figure 5.1 8-Pin MSOP Package Outline - 3x3mm Body 0.65mm Pitch Table 5.1 8-Pin MSOP Package Parameters
MIN A A1 A2 D E E1 H L L1 e 0.80 0.05 0.75 2.80 4.65 2.80 0.08 0.40 NOMINAL ~ ~ 0.85 3.00 4.90 ~ ~ ~ 0.95 REF 0.65 BSC 0o 0.22 ~ ~ ~ ~ 8o 0.38 0.10 MAX 1.10 0.15 0.95 3.20 5.15 3.20 0.23 0.80 REMARKS Overall Package Height Standoff Body Thickness X Body Size Y Span Y body Size Lead Foot Thickness Lead Foot Length Lead Length Lead Pitch Lead Foot Angle Lead Width Coplanarity
W ccc
Notes: 1. Controlling Unit: millimeters. 2. Tolerance on the true position of the leads is 0.065 mm maximum. 3. Package body dimensions D and E1 do not include mold protrusion or flash. Dimensions D and E1 to be determined at datum plane H. Maximum mold protrusion or flash is 0.15mm (0.006 inches) per end, and 0.15mm (0.006 inches) per side. 4. Dimension for foot length L measured at the gauge plane 0.25 mm above the seating plane. 5. Details of pin 1 identifier are optional but must be located within the zone indicated.
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