LM1946N National Semiconductor, LM1946N Datasheet
LM1946N
Specifications of LM1946N
LM1946
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LM1946N Summary of contents
Page 1
... LED or microproc- essor One side of the load can be grounded (not possible with ordinary comparator designs) which is important for auto- motive systems Typical Application Circuit Lamp Fault Detector C 1995 National Semiconductor Corporation TL H 8707 Features Five independent comparators Y Capable per output ...
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... Absolute Maximum Ratings If Military Aerospace specified devices are required please contact the National Semiconductor Sales Office Distributors for availability and specifications Supply Voltage (V and Input Pins) CC Survival Voltage (T 100 ms) s Operational Voltage Internal Power Dissipation (Note 1) Internally Limited Electrical Characteristics 9V Parameter Quiescent Current All Outputs ‘ ...
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... Connection Diagram Order Number LM1946N or LM1946M See NS Package Number M20B or N20A Typical Test Circuit Simplified Comparator Schematic TL H 8707 – 8707 – 8707– 23 ...
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Typical Performance Characteristics sat O Peak Iset vs Temperature Test Threshold Quiescent Current Quiescent Current Temperature V set Iset vs Temperature Iset vs Temperature Common ...
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Application Hints THEORY OF OPERATION UNDER-CURRENT LIMIT DETECTOR TL H 8707 – 6 Lamp Fault Detector FIGURE 3 Equivalent Automotive Lamp Circuit The diagram of Figure 3 represents the typical lamp circuit found in most automobiles Switch S1 represents a ...
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Application Hints (Continued) Typical values are Iset Vthrshld 2k) 100 For values of sense ...
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Application Hints (Continued) One solution is to use a low cost thermistor in conjunction with some low-TC resistors (see Figure 8 ) There are three fixed resistors and one thermistor This is an NTC thermistor since it has a negative ...
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Application Hints (Continued) FIGURE 10 Using the LM1946 as an Over-Current Limit Detector and R4 again allow the system designer to tailor the thresh- old limit to the V I characteristics of each particular system The input threshold voltage is ...
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Application Hints (Continued) FIGURE 12 Comparator Input Stage THE OUTPUT SECTION The output section of the LM1946 is different from most automotive comparators as it employs high beta proprietary PNP transistors which are very rugged and capable of high- er ...
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Application Hints (Continued) MORE NOISE FILTERING The current flowing through the sense resistor and certain loads can sometimes be very noisy particularly when the load motor or switching supply Large amounts of noise on the supply line ...
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Circuit Schematic 11 ...
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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 20-Lead Molded Dip (N) Order Number LM1946N NS Package Number N20A 2 A critical component is any component of a life ...