LM2591 National Semiconductor, LM2591 Datasheet
LM2591
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LM2591 Summary of contents
Page 1
... The LM2591HV operates at a switching frequency of 150 kHz thus allowing smaller sized filter components than what would be needed with lower frequency switching regulators. Available in a standard 5-lead TO-220 package with several different lead bend options, and a 5-lead TO-263 Surface mount package ...
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... T ≤ +125˚C J 4.5V to 60V LM2591HV-3.3 Units (Limits) Typ Limit (Note 3) (Note 4) 3.3 3.168/3.135 V(min) 3.432/3.465 V(max) 77 LM2591HV-5.0 Units (Limits) Typ Limit (Note 3) (Note 4.800/4.750 V(min) 5.200/5.250 V(max LM2591HV-ADJ Units (Limits) Typ ...
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... Note 5: External components such as the catch diode, inductor, input and output capacitors can affect switching regulator system performance. When the LM2591HV is used as shown in the Figure 1 test circuit, system performance will be as shown in system parameters section of Electrical Characteristics. Note 6: The switching frequency is reduced when the second stage current limit is activated. The amount of reduction is determined by the severity of current overload ...
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... Note 13: Junction to ambient thermal resistance with the TO-263 package tab soldered to a single sided printed circuit board with 2.5 in Note 14: Junction to ambient thermal resistance with the TO-263 package tab soldered to a double sided printed circuit board with 3 in the LM2591HVS side of the board, and approximately 16 in model in Switchers Made Simple available at http://power.national.com. ...
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Typical Performance Characteristics Switch Current Limit Operating Quiescent Current Minimum Operating Supply Voltage (Circuit of Figure 1) (Continued) 10129306 10129308 10129310 5 Dropout Voltage 10129307 Shutdown Quiescent Current 10129309 Feedback Pin Bias Current 10129311 www.national.com ...
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Typical Performance Characteristics Switching Frequency ON/OFF Pin Current (Sinking) Continuous Mode Switching Waveforms V = 20V 5V OUT µ 100 µF, C OUT A: Output Pin Voltage, 10V/div. B: Inductor Current ...
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... V = 20V ESR = 100 mΩ µ Output Voltage, 100 mV/div. (AC) 10129321 B: 250 Load Pulse Horizontal Time Base: 200 µs/div. 10129381 Order Number LM2591HVS-3.3, LM2591HVS-5. 5V 250 OUT LOAD = 150 µF, C ESR = 90 mΩ OUT OUT Surface Mount Package ...
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Test Circuit and Layout Guidelines Component Values shown are for V = 15V 5V 1A. OUT LOAD C — 470 µF, 50V, Aluminum Electrolytic Nichicon “PM Series” — 220 µF, 25V Aluminum Electrolytic, ...
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Block Diagram Pin Functions +V (Pin 1) — This is the positive input supply for the IC IN switching regulator. A suitable input bypass capacitor must be present at this pin to minimize voltage transients and to supply the switching ...
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... Inductor Value Selection Guides (For Continuous Mode Operation) www.national.com FIGURE 2. LM2591HV-3.3 FIGURE 3. LM2591HV-5.0 10 10129365 10129366 ...
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... Inductor Value Selection Guides (For Continuous Mode Operation) (Continued) FIGURE 4. LM2591HV-ADJ FIGURE 5. Current Ripple Ratio 11 10129367 10129368 www.national.com ...
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Inductor Value Selection Guides Coilcraft Inc. Coilcraft Inc., Europe Pulse Engineering Inc. Pulse Engineering Inc., Europe Renco Electronics Inc. Schott Corp. Cooper Electronic Tech. (Coiltronics) TDK FIGURE 6. Contact Information for Suggested Inductor Manufacturers www.national.com (For Continuous Mode Operation) (Continued) ...
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... IN e instead of the steady energy values. The worst CLIM case I for the LM2591HV is 3A. The Energy rating CLIM depends on the Inductance. See Example 2 below. 4. The nomographs were generated by allowing a greater amount of percentage current ripple in the Inductor as the maximum rated load decreases (see Figure 5). This was done to permit the use of smaller inductors at light loads. Figure 5 however shows only the ’ ...
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... Buck regulators require a diode to provide a return path for the inductor current when the switch turns off. This must be a fast diode and must be located close to the LM2591HV using short leads and short printed circuit traces. Because of their very fast switching speed and low forward voltage drop, Schottky diodes provide the best performance, especially in low output voltage applications (5V and lower) ...
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Application Information UNDERVOLTAGE LOCKOUT Some applications require the regulator to remain off until the input voltage reaches a predetermined voltage. An und- ervoltage lockout feature applied to a buck regulator is shown in Figure 8, while Figure 9 and Figure ...
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... For example, when convert- ing +20V to −12V, the regulator would see 32V between the input pin and ground pin. The LM2591HV has a maximum input voltage spec of 60V. Additional diodes are required in this regulator configuration. ...
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... This type of inverting regulator can require relatively large amounts of input current when starting up, even with light loads. Input currents as high as the LM2591HV current limit (approx 4A) are needed for at least more, until the output reaches its nominal output voltage. The actual time depends on the output voltage and the size of the output capacitor ...
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Application Information FIGURE 12. Inverting Regulator Ground Referenced Shutdown FIGURE 13. Inverting Regulator Ground Referenced Shutdown using Opto Device LAYOUT SUGGESTIONS As in any switching regulator, layout is very important. Rap- idly switching currents associated with wiring inductance can generate ...
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... Physical Dimensions inches (millimeters) unless otherwise noted Order Number LM2591HVT-3.3, LM2591HVT-5.0 5-Lead TO-220 Bent and Staggered Package or LM2591HVT-ADJ NS Package Number T05D 19 www.national.com ...
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... Physical Dimensions Order Number LM2591HVS-3.3, LM2591HVS-5.0 or LM2591HVS-ADJ LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or ...