EMC1422 SMSC Corporation, EMC1422 Datasheet

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... PRODUCT FEATURES GENERAL DESCRIPTION The EMC1422 is a high accuracy, low cost, System Management Bus (SMBus) temperature sensor. Advanced features such as Resistance Error Correction (REC), Beta Compensation (to support 90nm and 65nm CPU diodes) and automatic diode type detection combine to provide a robust solution for complex environmental monitoring applications ...

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... EMC1422-1-ACZL-TR FOR 8 PIN, MSOP LEAD-FREE ROHS COMPLIANT PACKAGE Note: See Table 1.1, "Part Selection" 80 ARKAY DRIVE, HAUPPAUGE, NY 11788 (631) 435-6000, FAX (631) 273-3123 Copyright © 2007 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 ...

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... Data Read Interlock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 6.2 Temperature Data Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 6.3 Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 6.4 Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 6.5 Conversion Rate Register 6.6 Limit Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 6.7 Scratchpad Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 6.8 Therm Limit Registers 6.9 External Diode Fault Register 6.10 Software Thermal Shutdown Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 6.11 Hardware Thermal Shutdown Limit Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 6.12 Channel Mask Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 SMSC EMC1422 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3 DATASHEET Revision 1.16 (03-15-07) ...

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... Consecutive ALERT Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 6.14 High Limit Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 6.15 Low Limit Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 6.16 THERM Limit Status Register 6.17 Filter Control Register 6.18 Product ID Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 6.19 SMSC ID Register (FEh 6.20 Revision Register (FFh Chapter 7 Package Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Revision 1.16 (03-15-07) 1°C Temperature Sensor with Hardware Thermal Shutdown 4 DATASHEET Datasheet SMSC EMC1422 ...

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... Temperature Sensor with Hardware Thermal Shutdown Datasheet List of Figures Figure 4.1 SMBus Timing Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Figure 5.1 System Diagram for EMC1422 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Figure 5.2 Block Diagram of Hardware Thermal Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Figure 5.3 Isolating ALERT and SYS_SHDN Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Figure 5.4 Temperature Filter Step Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Figure 5.5 Temperature Filter Impulse Response Figure 5 ...

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... Table 4.2 Write Byte Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Table 4.3 Read Byte Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Table 4.4 Send Byte Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Table 4.5 Receive Byte Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Table 4.6 Alert Response Address Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Table 5.1 Supply Current vs. Conversion Rate for EMC1422 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Table 5.2 SYS_SHDN Threshold Temperature Table 5.3 EMC1422 Temperature Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Table 6.1 Register Set in Hexadecimal Order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Table 6 ...

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... Temperature Sensor with Hardware Thermal Shutdown Datasheet Chapter 1 Block Diagram EMC1422 Switching Current Analog ΔΣ ADC Mux DP1 DN1 Internal Temp Diode 1.1 Part Selection The EMC1422 device configuration is highlighted below. PART SMBUS EXTERNAL NUMBER ADDRESS DIODES EMC1422 - 1 100_1100b SMSC EMC1422 V DD External Temperature Register(s) ...

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... Chapter 2 Pin Description Table 2.1 EMC1422 Preliminary Pin Description PIN NUMBER NAME 1 VDD SYS_SHDN 5 GND 6 ALERT 7 SMDATA 8 SMCLK The pin types are described below: Power - these pins are used to supply either VDD or GND to the device. AIO - Analog Input / Output Digital Input. ...

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... Electrical Specifications V = 3.0V to 3.6V -40°C to 125°C, all typical values CHARACTERISTIC SYMBOL Supply Voltage V DD Supply Current I DD SMSC EMC1422 Table 3.1 Absolute Maximum Ratings Refer to JEDEC Spec. J-STD- Table 3.2 Electrical Specifications A MIN TYP MAX UNITS DC Power 3.0 3.3 3.6 V 150 220 ...

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... ALERT and SYS_SHDN pins 0 DATASHEET Datasheet CONDITIONS 0°C < T < 85°C A +20°C < T < +100°C DIODE 0°C < T < 85°C A -40°C < T < 127°C DIODE EMC1422, default settings Connected across external diode I = 8mA SINK Temp selection read Note 3.1 SMSC EMC1422 ...

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... HD:DAT Data Setup Time t SU:DAT Clock Low Period t LOW Clock High Period t HIGH Clock/Data Fall time t FALL Clock/Data Rise time t RISE Capacitive Load C LOAD SMSC EMC1422 = 27°C unless otherwise noted. A MIN TYP MAX UNITS SMBus Interface 2 Tolerant DD -0.3 0 Tolerant - ...

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... Chapter 4 System Management Bus Interface Protocol 4.1 System Management Bus Interface Protocol The EMC1422 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 ...

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... When it detects that the ALERT pin is asserted, the host will send the Alert Response Address (ARA) to the general address of 000_1100b. All devices with active interrupts will respond with their client address as shown in Table Table 4.6 Alert Response Address Protocol ALERT RESPONSE START ADDRESS 1 7 SMSC EMC1422 Table 4.3 Read Byte Protocol ACK START SLAVE RD ADDRESS Table 4 ...

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... Note: Other addresses are available. Contact SMSC for more information. 4.8 SMBus Timeout The EMC1422 supports SMBus Timeout. If the clock line is held low for longer than 30ms, the device will reset its SMBus protocol. This function can be disabled by clearing the TIMEOUT bit in the Consecutive Alert Register (see Revision 1.16 (03-15-07) 1° ...

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... EMC1422 and using that data to control the speed of one or more fans. The EMC1422 has two levels of monitoring. The first provides a maskable ALERT signal to the host when measured temperatures meet or exceed user programmable limits. This allows the EMC1422 to be used as an independent thermal watchdog to warn the host of temperature hot spots without direct control by the host ...

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... When enabled, the dynamic averaging will affect the average supply current based on the chosen conversion rate as shown in Table 5.1 Supply Current vs. Conversion Rate for EMC1422 CONVERSION RATE (DEFAULT sec ...

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... ALERT Output The ALERT pin is an open drain output and requires a pull-up resistor to V operation: interrupt mode and comparator Mode. The mode of the ALERT output is selected via the ALERT / COMP bit in the Configuration Register (see SMSC EMC1422 Hardware Thermal Shutdown Software Conversion ...

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... ALERT and SYS_SHDN pins must be isolated from their respective busses during this time. One method of isolating this pin is shown in VDD 1 DP1 2 DN1 3 SYS_SHDN 4 Figure 5.3 Isolating ALERT and SYS_SHDN Pins Revision 1.16 (03-15-07) 1°C Temperature Sensor with Hardware Thermal Shutdown Figure 5.3. +3.3V 4.7K - 33K 10 SMCLK 9 SMDATA 8 ALERT 7 GND 18 DATASHEET Datasheet +2 22K Shared Alert/ SMSC EMC1422 ...

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... Diode Faults The EMC1422 detects an open on the DP and DN pins, and a short across the DP and DN pins. For each temperature measurement made, the device checks for a diode fault on the external diode channel(s). When a diode fault is detected, the ALERT pin asserts (unless masked, see and the temperature data reads 00h in the MSB and LSB registers (note: the low limit will not be checked) ...

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... Disabled. The typical filter performance is shown in 90 Disabled Figure 5.4 Temperature Filter Step Response Revision 1.16 (03-15-07) 1°C Temperature Sensor with Hardware Thermal Shutdown Figure 5.4 Filter Step Response Level1 Level2 Samples 20 DATASHEET Datasheet and Figure 5. SMSC EMC1422 ...

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... Figure 5.6 shows a block diagram of the temperature measurement circuit. The negative terminal for the remote temperature diode, DN, is internally biased with a forward diode voltage referenced to ground. SMSC EMC1422 Filter Impulse Response Disabled Level1 Samples where: ⎛ ⎞ Boltzmann’s constant I ⎜ ...

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... All other bits of the low byte register are set to zero. The EMC1422 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° ...

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... For the default range, all temperatures > +127.875°C will be reported as +127.875°C. Note 5.4 For the extended range, all temperatures > +191.875°C will be reported as +191.875°C. 5.12 External Diode Connections The EMC1422 is hard-wired to measure a specific kind of thermal diode and none of the measurement options can be changed by software ...

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... Controls the conversion rate for updating temperature data (mirrored at address 04h) 24 DATASHEET Datasheet DEFAULT VALUE PAGE 00h Page 26 00h 00h Page 26 00h Page 27 06h Page 28 (4/sec) 55h (85°C) 00h (0°C) Page 29 55h (85°C) 00h (0°C) 00h Page 27 06h Page 28 (4/sec) SMSC EMC1422 ...

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... R-C High Limit Status 36h R-C Low Limit Status 37h R THERM Limit Status SMSC EMC1422 FUNCTION Stores the 8-bit high limit for the Internal Diode (mirrored at address 05h) Stores the 8-bit low limit for the Internal Diode (mirrored at address 06h) Stores the integer portion of the ...

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... The individual Status Register bits are cleared when the 26 DATASHEET Datasheet DEFAULT VALUE PAGE 00h Page 34 Table 6.21 Page 35 5Dh Page 35 01h Page DEFAULT 00h - - - - 00h 00h - - - - 00h DEFAULT FAULT THERM HWSD 00h Section SMSC EMC1422 6.9, ...

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... Table Bit 1 - DAVG_DIS - Disables the dynamic averaging feature on all temperature channels. ‘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 SMSC EMC1422 Table 6.4 Configuration Register ...

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... Table 6.6 Conversion Rate All others 28 DATASHEET Datasheet DEFAULT 06h CONV[3:0] (4/sec) Table 6.6. CONVERSIONS / SECOND (default SMSC EMC1422 ...

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... R/W Scratchpad 12h R/W Scratchpad 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. SMSC EMC1422 Table 6.7 Temperature Limit Registers 128 64 ...

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... Table 6.10 External Diode Fault Register DATASHEET Datasheet DEFAULT 55h (85°C) 55h (85°C) 0Ah (10° DEFAULT - FLT - 00h DEFAULT - EXTSYS INTSYS 00h SMSC EMC1422 ...

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... Bit 0 - INTMASK - Masks the ALERT pin from asserting when the Internal Diode temperature is out of limit. ‘0’ (default) - The Internal Diode channel will cause the ALERT pin to be asserted out of limit. ‘1’ - The Internal Diode channel will not cause the ALERT pin to be asserted out of limit. SMSC EMC1422 ...

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... 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. Revision 1.16 (03-15-07) 1°C Temperature Sensor with Hardware Thermal Shutdown Table 6.14 Consecutive ALERT Register TIME CTHRM[2:0] OUT 32 DATASHEET Datasheet DEFAULT CALRT[2:0] - 70h SMSC EMC1422 ...

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... Bit 1 - EHIGH - This bit is set when the External Diode channel exceeds its programmed high limit. Bit 0 - IHIGH - This bit is set when the Internal Diode channel exceeds its programmed high limit. SMSC EMC1422 Table 6.15. The default setting is 4 consecutive out of limit NUMBER OF CONSECUTIVE OUT OF LIMIT ...

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... Temperature Sensor with Hardware Thermal Shutdown Table 6.17 Low Limit Status Register Table 6.18 THERM Limit Status Register Table 6.19 Filter Configuration Register DATASHEET Datasheet DEFAULT - ELOW ILOW 00h DEFAULT - E THERM ITHERM 00h DEFAULT - - FILTER[1:0] 00h SMSC EMC1422 ...

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... SMSC ID Register (FEh) ADDR. R/W REGISTER FEh R SMSC ID The Manufacturer ID register contains an 8 bit word that identifies the SMSC as the manufacturer of the EMC1422. 6.20 Revision Register (FFh) ADDR. R/W REGISTER FFh R Revision The Revision register contains an 8 bit word that identifies the die revision. ...

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Chapter 7 Package Information 3 D PIN 1 IDENTIFIER AREA (D/2 X E1/ TOP VIEW C SEATING PLANE A1 ccc C SIDE VIEW C GAUGE PLANE 0.25 SEATING PLANE 0° - 8° DETAIL ...