LM621N NSC [National Semiconductor], LM621N Datasheet
LM621N
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LM621N Summary of contents
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... Directly interfaces to pulse-width modulator output(s) Y via OUTPUT INHIBIT (PWM magnitude) and DIREC- TION (PWM sign) inputs Direct interface to Hall sensors Y Outputs are current limited Y Undervoltage lockout Y Order Number LM621N See NS Package Number N18A August 1992 TL H 8679 – 1 RRD-B30M115 Printed ...
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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 V CC1 V CC2 Logic Inputs (Note 1) V CC1 Logic Input Clamp Current Output Voltages Output Currents ...
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Electrical Characteristics (See Notes) (Continued) Parameter Conditions DEAD-TIME SECTION High Level Input Voltage DIRECTION Pin 3 e OUTPUT INHIBIT DEAD-TIME ENABLE Pin 17 High Level Input Current DIRECTION Pin 3 e OUTPUT INHIBIT DEAD-TIME ENABLE Low ...
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Typical Performance Characteristics Selection Graph for R and Temperature sat Description of Inputs and Outputs Pin 5V) The logic and clock power supply pin a CC1 Pin 2 DIRECTION This input determines the direction ...
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Functional Description The commutation decoder receives Hall-sensor inputs HS1 HS2 and HS3 and SELECT input This block de- codes the gray-code sequence to the required motor-drive sequence The dead-time generator monitors the DIRECTION input and inhibits the ...
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Three-Phase Motor Commutation TABLE I LM621 Commutation Decoder Truth Table Sensor Position Sensor Inputs Phasing Range HS1 0–60 0 60–120 0 30 deg 120–180 0 180–240 1 240–300 1 300–360 1 0–60 1 60–120 1 60 deg 120–180 1 180–240 ...
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Dead-Time Feature The DEAD-TIME ENABLE input is used to enable this fea- ture (by connecting 5V to pin 3) The reason for providing a this feature is that the external power switches are usually totem-pole structures Since these structures switch ...
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Dead-Time Feature (Continued) Dead-time is defined as the time the outputs are blanked off (to prevent shoot-through currents) after a direction change input See Figure 3 It can be seen that the dead-time is two clock periods Since the dead-time ...
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Typical Applications (Continued) FIGURE 5 Commutation of Three-Phase Motor (MOSFET Switches 8679 – 10 ...
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Typical Applications (Continued) FOUR-PHASE EXAMPLE Figure 6 is typical of the circuitry used to commutate a four- phase motor using the LM621 This application is seen to differ from the three-phase application example in that the LM621 outputs are utilized ...
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Typical Applications (Continued) FIGURE 7 Half-Wave Drive of Y-Configured Motor 8679 – 12 ...
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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 Molded Dual-in-Line Package (N) Order Number LM621N NS Package Number N18A 2 A critical component is any component of a life ...