LM1572EVAL National Semiconductor, LM1572EVAL Datasheet
LM1572EVAL
Specifications of LM1572EVAL
Related parts for LM1572EVAL
LM1572EVAL Summary of contents
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... The LM1572 is available in a TSSOP-16 package with an adjustable output or fixed outputs of 5V and 3.3V. The ad- justable version can be set between 2.42V and 5V. Typical Applications (Fixed/Adjustable Voltage Parts) © 2002 National Semiconductor Corporation Features n 500kHz clock allows small, surface mount components n 150mΩ MOSFET switch n Guaranteed load current of 1 ...
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Typical Applications (Fixed/Adjustable Voltage Parts) Connection Diagram Pin Description BOOT (Pin 1) - Bootstrap pin. It provides the upper rail for the floating driver stage of the internal MOSFET switch, the lower rail being the switching node (Pins 5 and ...
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Pin Description (Continued) V (Pins 3,4) - This is the input supply to the power stage IN (connected to the Drain of the switching MOSFET). To aid thermal dissipation from the die, two pins are used for this function. Both ...
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Block Diagram www.national.com 4 20033312 ...
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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. ESD Tolerance (Note 2) Input Voltage SD Pin Voltage FB Pin Voltage (All Options) Storage Temp. Range Electrical Characteristics Unless otherwise specified, all limits are guaranteed for T otherwise noted. Boldface apply over the temperature extremes. ’ ...
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Electrical Characteristics Unless otherwise specified, all limits are guaranteed for T otherwise noted. Boldface apply over the temperature extremes. ’V regulation. Symbol Parameter I Softstart Pin Current SS I Shutdown Supply Current SD I Standby Supply Current STDBY V Undervoltage ...
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Typical Performance Characteristics Efficiency (3.3V OUT Efficiency (5V OUT Supply Current vs Voltage on Shutdown Pin ) 20033301 ) 20033303 20033305 7 Characteristics of Switch 20033302 Supply Current vs Load 20033304 Characteristics of Shutdown Pin 20033306 www.national.com ...
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Typical Performance Characteristics Shutdown Pin Current at Shutdown Threshold Frequency Foldback Operating Feedback Pin Current vs Input Voltage www.national.com (Continued) Shutdown Supply Current vs Input Voltage 20033307 Characteristics of Feedback Pin 20033309 20033311 8 20033308 20033310 ...
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Application Information Resistive Divider Calculation For the adjustable part, the voltage on the feedback pin is set to 2.42V under regulation. This is achieved by means of a resistive divider, as indicated in the Typical Applications for the adjustable part. ...
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Application Information harmonic instability is not of concern if any one or more of the above conditions are not true. And in that case, the inductor selection considerations become identical to those for voltage mode control. Note that the worst ...
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Application Information inductor for the application. 10µ more widely available standard value, and very close to the optimum value too, and would therefore be a good choice too. Note that inductances larger than 15µH are not recommended in ...
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Application Information Output Capacitor Selection In voltage mode control, the esr of the output capacitor plays an important role in the feedback loop. Therefore in such cases usually cautioned against reducing the esr too much. But keeping the ...
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Application Information It can be shown that this protection feature is vital to avoiding overstress during overload and even under normal startup/ powerup. Consider what happens if the output of a buck converter is at zero volts with the maximum ...
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Application Information Loop Compensation Since the LM1572 uses current mode control, the loop re- sponse does not involve the inductor. The error amplifier can be modeled as a transconductance amplifier with a large output impedance of 200k of resistance in ...
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... Therefore, the effect of the tolerance of the resistors in an internal resistive divider fixed itself (this FB voltage parts, can be ignored. Manufacturer National Semiconductor International Rectifier General Semiconductor Gowanda Vishay-Sprague 15 -V )*Tol/ ...
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Application Information Bill of Material for LM1572 Evaluation Board Designator Description C2, C3 0.1µF/50V C4 3.3nF/50V C6 100µF/10V * Rated continuous 1A load. Use SMP5025-821K (or equivalent) for higher continuous load rating. **Increase C5 to 0.18µF for regulation ...
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... 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 systems which, (a) are intended for surgical implant ...