LM99CIMMX NSC [National Semiconductor], LM99CIMMX Datasheet
LM99CIMMX
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LM99CIMMX Summary of contents
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LM99 ± 1˚C Accurate, High Temperature, Remote Diode Temperature Sensor with Two-Wire Interface General Description The LM99 is an 11-bit remote diode temperature sensor with a 2-wire System Management Bus (SMBus) serial interface. The LM99 accurately measures: (1) its own ...
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... Connection Diagram Ordering Information Part Number LM99CIMM LM99-1CIMM LM99CIMMX LM99-1CIMMX Pin Descriptions Label Pin # D− 3 T_CRIT_A 4 GND 5 ALERT 6 SMBData 7 SMBCLK 8 www.national.com MSOP-8 TOP VIEW Package NS Package Marking Number MUA08A T17C (MSOP-8) MUA08A T20C (MSOP-8) MUA08A T17C (MSOP-8) MUA08A ...
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Typical Application 3 20053803 www.national.com ...
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Absolute Maximum Ratings Supply Voltage Voltage at SMBData, SMBCLK, ALERT, T_CRIT_A Voltage at Other Pins D− Input Current Input Current at All Other Pins (Note 2) Package Input Current (Note 2) SMBData, ALERT, T_CRIT_A Output Sink Current Storage Temperature Soldering ...
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Logic Electrical Characteristics DIGITAL DC CHARACTERISTICS Unless otherwise noted, these specifications apply for V limits apply for MIN Symbol Parameter SMBData, SMBCLK INPUTS V Logical “1” Input Voltage IN(1) V Logical ...
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SMBus Communication Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. DC and AC electrical specifications do not apply when operating the device beyond its rated operating conditions. Note 2: When the input voltage ...
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Functional Description The LM99 temperature sensor incorporates a delta V based temperature sensor using a Local or Remote diode and a 10-bit plus sign ∆Σ ADC (Delta-Sigma Analog-to- Digital Converter). The LM99 is compatible with the serial SMBus version ...
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Functional Description FIGURE 3. ALERT Comparator Temperature Response Diagram 1.2.2 ALERT Output as an Interrupt The LM99’s ALERT output can be implemented as a simple interrupt signal when it is used to trigger an interrupt service routine. In such ...
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Functional Description 1. Master Senses SMBus alert line low 2. Master sends a START followed by the Alert Response Address (ARA) with a Read Command. 3. Alerting Device(s) send ACK. 4. Alerting Device(s) send their Address. While transmitting their ...
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Functional Description Remote temperature data is represented by an 11-bit, two’s complement word with an LSB (Least Significant Bit) equal Actual Remote Diode Temperature,˚C 120 125 126 130 135 140 Output is 11-bit two’s complement word. LSB = 0.125 ...
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Functional Description 1.9 COMMUNICATING WITH THE LM99 The data registers in the LM99 are selected by the Com- mand Register. At power-up the Command Register is set to “00”, the location for the Read Local Temperature Register. The Command ...
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Functional Description 1.9.1 SMBus Timing Diagrams LM99 Timing Diagram (a) Serial Bus Write to the internal Command Register followed by a the Data Byte (b) Serial Bus Write to the Internal Command Register (c) Serial Bus Read from a ...
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Functional Description 1.11 DIGITAL FILTER order to suppress erroneous remote temperature readings due to noise, the LM99 incorporates a user-configured digital a) Step Response FIGURE 8. Filter Output ...
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Functional Description 1.12 FAULT QUEUE In order to suppress erroneous ALERT or T_CRIT triggering the LM99 incorporates a Fault Queue. The Fault Queue acts to insure a remote temperature measurement is genuinely beyond a HIGH, LOW or T_CRIT setpoint ...
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LM99 Registers (Continued) Command Select Address Read Address Write Address < > < > P7:P0 hex P7:P0 hex 10h NA 11h 11h 12h 12h 13h 13h 14h 14h 19h 19h 20h 20h 21h 21h B0h-BEh B0h-BEh BFh BFh FEh ...
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LM99 Registers (Continued) 2.4 CONFIGURATION REGISTER (Read Address 03h / Write Address 09h ALERT mask RUN/STOP Power up default is with all bits “0” (zero) D7: ALERT mask: When set to “1” ALERT interrupts are masked. D6: ...
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LM99 Registers (Continued) 2.8 REMOTE TEMPERATURE OFFSET REGISTERS (RTOHB and RTOLB) (Read / Write Address 11h): BIT Value SIGN For RTOHB: Remote Temperature Offset High Byte. Power-on default is LHIGH = RHIGH = 0˚C. 1 LSB = 1˚C. Two’s ...
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Application Hints The LM99 can be applied easily in the same way as other integrated-circuit temperature sensors, and its remote diode sensing capability allows used in new ways as well. It can be soldered to a ...
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Application Hints (Continued) 3.2 PCB LAYOUT FOR MINIMIZING NOISE FIGURE 11. Ideal Diode Trace Layout In a noisy environment, such as a processor mother board, layout considerations are very critical. Noise induced on traces running between the remote temperature ...
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... National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications. inches (millimeters) unless otherwise noted JEDEC Registration Number MO-187 Order Number LM99CIMM or LM99CIMMX NS Package Number MUA08A 2. A critical component is any component of a life ...