lm74a-5-mda National Semiconductor Corporation, lm74a-5-mda Datasheet
lm74a-5-mda
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lm74a-5-mda Summary of contents
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... General Description The LM74A is a temperature sensor, Delta-Sigma analog-to- digital converter with an SPI and MICROWIRE compatible interface in die form. The host can query the LM74A at any time to read temperature. A shutdown mode decreases power consumption to less than 10 µA. This mode is useful in systems where low average power consumption is critical. ...
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... Function 2 Y +0.585 mm +0.314 mm -0.554 mm n/a +0.277 mm +0.569 mm Transport Media Typical Connection From and to Controller From Controller Ground No Connection From Controller DC Voltage from 4.5V to 5.5V for the LM74A-5 and 3.0V to 3.6V for the LM74A-3. Bypass with a 0.1 µF ceramic capacitor. Can go to GND connection ...
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Typical Application FIGURE 1. COP Microcontroller Interface 3 20017703 www.national.com ...
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... O_TRI-STATE Current www.national.com Operating Ratings (Note 1) −0.3V to 6.0V Operating Temperature Range + −0. 0.3V Specified Temperature Range 5 mA (Note 4) LM74A 20 mA Supply Voltage Range (+V −65˚C to +150˚C LM74-5 MDA 2000V LM74-3 MDA 200V + = 4.5V to 5.5V for the LM74-5 MDA and all other limits T ...
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... Note 7: Limits are guaranteed to National’s AOQL (Average Outgoing Quality Level). Note 8: This specification is provided only to indicate how often temperature data is updated. The LM74A can be read at any time without regard to conversion state (and will yield last conversion result). A conversion in progress will not be interrupted. The output shift register will be updated at the completion of the read and a new conversion restarted. Note 9: For best accuracy, minimize output loading. Higher sink currents can affect sensor accuracy with internal heating. This can cause an error of 0.64˚ ...
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Timing Diagrams (Continued) Temperature-to-Digital Transfer Function (Non-linear scale for clarity) www.national.com FIGURE 3. TRI-STATE Data Output Timing Diagram FIGURE 4. Data Input Timing Diagram FIGURE 5. 6 20017705 20017706 20017708 ...
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TRI-STATE Test Circuit Typical Performance Characteristics Average Power-On Reset Voltage vs Temperature Temperature Error FIGURE 6. Static Supply Current vs Temperature 20017723 20017726 7 20017707 20017721 www.national.com ...
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... The part will detect the last eight bits shifted into the register. The receive phase can last periods. All ones must be shifted in order to place the part into shutdown. A zero in any location will take the LM74A out of shutdown. The following codes should only be transmitted to the LM74A: • ...
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... D0–D15 set hex sets Continuous conversion mode. Note: setting D0-D15 to any other values may place the LM70 into a manufacturer’s test mode, upon which the LM74A will stop responding as described. These test modes are to be used for National Semiconductor production testing only. See Section 1.2 Serial Bus Interface for a complete discussion ...
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Serial Bus Timing Diagrams a) Reading Continuous Conversion - Single Eight-Bit Frame b) Reading Continuous Conversion - Two Eight-Bit Frames www.national.com 20017714 c) Writing Shutdown Control FIGURE 7. Timing Diagrams 10 20017715 20017718 ...
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... Application Hints 3.1 LIGHT SENSITIVITY The LM74A in die form should not be exposed to ultraviolet light. Exposing the LM74A to bright sunlight will not immedi- atly cause a change in the output reading. Our experiments show that directly exposing the circuit side (pad side) of the 2 die to high intensity (≥ 1mW/cm ) ultraviolet light, centered at 4 ...
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... Revision History Date Revision 10/12/2004 1. Added LM74A-3 MDA specifications. 2. Updated order number of LM74A MDA to LM74A-5 MDA. 07/17/2001 Released to web originaly. Bond Pad Layout Order Number LM74A-5 MDA or LM74A-3 MDA For Bond Pad Mechanical Dimensions see Connection Diagram Section 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 ...