lm5021na-2 National Semiconductor Corporation, lm5021na-2 Datasheet
lm5021na-2
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lm5021na-2 Summary of contents
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... This high performance 8-pin IC has total propagation delays less than 100nS and a 1MHz ca- pable oscillator that is programmed with a single resistor. Simplified Application Diagram © 2005 National Semiconductor Corporation Features n Ultra Low Start-up Current (25 µA maximum) n Current Mode Control n Skip Cycle Mode for Low Standby Power ...
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... Order Number LM5021MM-1 80% Duty Cycle Limit LM5021MMX-1 80% Duty Cycle Limit LM5021NA-1 80% Duty Cycle Limit LM5021MM-2 50% Duty Cycle Limit LM5021MMX-2 50% Duty Cycle Limit LM5021NA-2 50% Duty Cycle Limit Pin Description PIN NAME DESCRIPTION 1 COMP Control input for the Pulse Width Modulator and Hiccup comparators. 2 VIN Input voltage ...
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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. VIN to GND VIN Clamp Continuous Current CS to GND RT to GND All other pins to GND Electrical ...
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Electrical Characteristics apply over the full Operating Junction Temperature Range. Unless otherwise specified (Continued) Symbol Parameter PWM COMPARATOR COMP to OUT delay Min Duty Cycle Max Duty Cycle (-1 Device) Max Duty Cycle (-2 Device) COMP to PWM ...
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Simplified Block Diagram FIGURE 1. 5 20144203 www.national.com ...
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Typical Performance Characteristics VIN Start-Up Current VIN Current vs OUT Load OUT Driver Current vs Temperature www.national.com Unless otherwise specified: T 20144204 VIN Voltage Falling vs VCC Voltage 20144206 Hiccup Mode Deadtime vs Softstart Capacitance 20144208 6 = 25˚C. J ...
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Typical Performance Characteristics Output Switching Frequency vs RT Detailed Operating Description START UP CIRCUIT Referring to Figure 2, the input capacitor C charged through the start-up resistor Rstart, when the recti- fied ac input voltage HV is applied. The VIN ...
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Detailed Operating Description (Continued) RELATIONSHIP BETWEEN INPUT CAPACITOR C V CAPACITOR C CC VCC The internal VCC linear regulator is enabled when VIN reaches 20V. The drop in VIN due to charge transfer from after the regulator ...
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Detailed Operating Description (Continued) frequency and the operational output frequency are the same. To set a desired output switching frequency (Fsw), the RT resistor can be calculated from: LM5021-1: LM5021-2: The LM5021 can also be synchronized to an external clock. ...
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Detailed Operating Description FIGURE 4. Waveform at SS and COMP Pin due to Continuous Overload www.national.com (Continued) FIGURE 3. Hiccup Mode Control 10 20144219 20144220 ...
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Detailed Operating Description FIGURE 5. Waveform at SS and COMP Pin due to Brief Overload SKIP CYCLE OPERATION During light load conditions, the efficiency of the switching power supply typically drops as the losses associated with switching and operating bias ...
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Detailed Operating Description www.national.com (Continued) FIGURE 6. Skip Cycle Control 12 20144222 ...
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Physical Dimensions unless otherwise noted www.national.com inches (millimeters) 8 Lead MSOP Package NS Package Number MUA08A 8 Lead MDIP Package NS Package Number N08E 14 ...
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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. For the most current product information ...