LM41 National Semiconductor, LM41 Datasheet
LM41
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LM41 Summary of contents
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... The LM41 can resolve tem- peratures up to 255˚C and down to -256˚C. The operating temperature range of the LM41 is 0˚C to +125˚C. Using Σ∆ ADC it measures +1.2V, +2.5V, +3.3V, +5V and +12V analog input voltages with internal scaling resistors. The address programming pin allows two LM41’ ...
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... Power supply voltage to be monitored scaling resistors +12V voltage monitoring input with Power supply voltage to be monitored scaling resistors 2 NS Package Package Transport Marking Number Media LM41 MTC14C 94 units per CIMT rail LM41 MTC14C 2500 units in CIMT tape and reel ...
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Block Diagram 3 20070303 www.national.com ...
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... ESD Susceptibility (Note 5) Human Body Model Machine Model Storage Temperature DC Electrical Characteristics The following specifications apply for V+ = +3.0 V wise specified in the conditions. Boldface limits apply for LM41CIMT +25˚ the ambient temperature of the LM41 perature of the remote thermal diode. ...
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TEMPERATURE-TO-DIGITAL CONVERTER CHARACTERISTICS Parameter Diode Source Current Diode Source Current High Current to Low Current Ratio ANALOG TO DIGITAL CONVERTER CHARACTERISTICS Symbol Parameter TUE Total Unadjusted Error(Note 11) Resolution DNL Differential Non-linearity Power Supply Sensitivity Input Resistance, all analog inputs ...
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... Note 2: All voltages are measured with respect to GND, unless otherwise noted. Note 3: When the input voltage ( any pin exceeds the power supplies (V IN components and/or ESD protection circuitry are shown below for the LM41’s pins. The nominal breakdown voltage of the zener is 6.5 V. SNP stands for snap-back device. www.national.com (Continued ...
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... If the theoretical input voltage was applied to an LM41 that has positive error, the LM41’s reading would be less than the theoretical. Note 12: The accuracy of the LM41CIMT is guaranteed when using the thermal diode of an Intel 90 nm Pentium 4 processor or any thermal diode with a non-ideality factor of 1.011 and series resistance of 3.33Ω ...
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Timing Diagrams FIGURE 1. Timing for Data Bits 0, 1 and Start Bit. See Section 1.2 "SensorPath BIT SIGNALING" for further details. www.national.com 8 20070304 ...
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Timing Diagrams (Continued) FIGURE 2. Timing for Attention Request and Reset. See Section 1.2 "SensorPath BIT SIGNALING" for further details. 9 20070305 www.national.com ...
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... National offers a royalty- free license in connection with its intellectual property rights in the SensorPath bus. The LM41 has one address pin to allow up to two LM41s to be connected to one SensorPath bus. The physical interface of SensorPath’s SWD signal is identical to the familiar indus- try standard SMBus SMBDAT signal ...
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... The LM41 will detect that the SWD becomes active Mtr0 within a period For a data read of "0", the LM41 SFEdet will not drive the SWD. For a data read of "1" the LM41 will start within t to drive the SWD low for a period of SFEdet t ...
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... During a read transaction, the EP bit is sent by the LM41 to the master to allow the master to check the received data before using it. FIGURE 5. Read Transaction, master reads data from LM41 1 ...
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... During a write trans- action, the EP bit is sent by the master to the LM41 to allow the LM41 to check the received data before using it. • Acknowledge (ACK) During the write transaction the ...
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... Attention Request Indication. • Masters are expected to use the attention request as a trigger to read results from the LM41. This is done in a sequence that covers all LM41s. This sequence is re- ferred to as "master sensor read sequence". ...
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Register Set 2.1 REGISTER SET SUMMARY P Bit Reg Register Add Name W R MSb Val 000 000 Device R * 00h Number 000 001 Manufacturer R 100Bh 0 01h ID 000 010 Device ID R ...
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... R/ O Add Name W R MSb Val Manufacturer 000 001 R 100Bh ID The manufacturer ID matches that assigned to National Semiconductor by the PCI SIG. This register may be used to identify the manufacturer of the device in order to perform manufacturer specific operations. www.national.com Bit 7 Bit 6 Bit Val ...
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... Fixed 0 The value of this register defines the capabilities of the LM41. The LM41 supports two functions, that of Temperature Measurement type (Function 1) and Voltage-Only Measurement type (Function 2). Please refer to the SensorPath specification for further details on other FuncDescriptor values. 2.7 DEVICE STATUS (Addr: 000 100; 04h) This register is set to the reset value by a Device Reset ...
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... RO Not supported. Will always read "0". 2.9 TEMPERATURE MEASUREMENT FUNCTION (TYPE - 0001) This section defines the register structure and operation of a Temperature Measurement function as it applies to the LM41. The FuncDescriptor value of this function is ‘0001’. 2.9.1 Operation The Temperature Measurement function as implemented in the LM41 supports 2 temperature zones, the LM41’s internal temperature (LM41’ ...
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... The resolution of the readout is defined in the Temperature Capabilities register. The resolution of the LM41 is fixed and cannot be modified by software. The temperature readout type is common to all the sensors and is signed two’s complement fixed point value. The readout type is specified in the Capabilities register of the function. ...
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... All LM41 temperature data has a common format. The LM41’s temperature data format is two’s complement and has 10-bits of resolution with the LSb having a weight of 0.5 ˚C. The LM41 can resolve temperature between +255.5 ˚C and -256 ˚C, inclusive. It can measure local temperatures between +85 ˚C and 0 ˚C and remote temperatures between +125 ˚C and 0 ˚C with an ± ...
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... Readout Resolution The resolution of the readout register is defined in the Voltage Capabilities register. The resolution of the LM41 is fixed and cannot be modified by software. The voltage readout format is common to all voltage sensors and is 9-bits unsigned. For over or under input voltage conditions the data is guaranteed to saturate at all "1"s or "0"s so long as Operating Ratings of the LM41 are adhered to ...
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... MSb Val Voltage 010 000 R 0051h Capabilities This register defines the format of the voltage data in the voltage readout register. The LM41 only supports one format for all voltage measurements as defined by the values of this register. Bit Type 2-0 RO Resolution. This field defines the total number of significant bits in the Voltage Readout field in the Readout register for this function ...
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... Bit Type 4-0 RO Low Rate Function This function is not supported by the LM41 and therefore this field is read only. 5 R/W ATE (Attention Enable). When set, this bit enables an Attention Request signal to be generated by the LM41, if one or more EN0-EN4 bits of this register are set. 0: Attention Request disabled (from enabled Temperature Sensor- default) ...
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... BIOS run time. The conversion rate is dependent on system physical requirements and limitations. The thermal response time of the MSOP package is one such requirement. Most systems will function properly with the default settings. The master scan rate is related to the conversion rate of the LM41. If attentions are enabled the conversion rate and scan rate will be equal. ...
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... Noise induced on traces running between the remote temperature diode sen- sor and the LM41 can cause temperature conversion errors. Keep in mind that the signal level the LM41 is trying to measure is in microvolts. The following guidelines should be followed: 1. Place the 100 pF and 0.1 µ ...
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... SensorPath Bus corrupt data is the most common symptom for noise coupled in SWD. A no-ACK is the symptom for noise coupled into the Device Number Select pin (ADD lowpass filter as well as a debouncing circuit are in- cluded in the LM41 that filter noise spikes less than 2.5 µsec in duration on the SWD signal. 26 ...
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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) Order Number LM41CIMT, or LM41CIMTX, NS Package Number MTC14C 2. A critical component is any component of a life ...