lm2738xsdx National Semiconductor Corporation, lm2738xsdx Datasheet
lm2738xsdx
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lm2738xsdx Summary of contents
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... Additional features include internal soft-start cir- cuitry to reduce in-rush current, cycle-by-cycle current limit, thermal shutdown, and output over-voltage protection. Typical Application Circuit © 2008 National Semiconductor Corporation Features ■ Space Saving LLP-8 and eMSOP-8 package ■ ...
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... Connection Diagrams 8-Pin LLP - TOP VIEW NS Package Number SDA08A Ordering Information Order Number Frequency Package Type Option LM2738XSD 1.6MHz LM2738XSDX LM2738YSD 0.55MHz LM2738YSDX LM2738XMY 1.6MHz LM2738XMYX 8-Lead eMSOP LM2738YMY 0.55MHz LM2738YMYX * Contact the local sales office for the lead-free package. Pin Descriptions ...
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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 Voltage Boost Voltage Boost to SW Voltage FB Voltage EN Voltage Junction Temperature ...
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Typical Performance Characteristics unless specified otherwise. Efficiency vs Load Current - "X" V Efficiency vs Load Current - "X" V Efficiency vs Load Current - "X" V www.national.com All curves taken Efficiency vs Load Current - ...
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Typical Performance Characteristics unless specified otherwise. Oscillator Frequency vs Temperature - "X" Current Limit vs Temperature Temperature FB All curves taken 12V Oscillator Frequency vs Temperature - "Y" 30049127 ...
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Typical Performance Characteristics unless specified otherwise. Line Regulation - "X" (V OUT Line Regulation - "X" (V OUT Load Regulation - "X" (V www.national.com All curves taken 1.5V 750mA) Line Regulation - "Y" (V OUT ...
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Typical Performance Characteristics unless specified otherwise. Load Regulation - "X" Switching vs Temperature Q Startup - "X" 3.3V 12, I =1.5A (Resistive Load)) OUT IN OUT All curves taken 3.3V) Load ...
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Block Diagram Application Information THEORY OF OPERATION The LM2738 is a constant frequency PWM buck regulator IC that delivers a 1.5A load current. The regulator has a preset switching frequency of either 550kHz (LM2738Y) or 1.6MHz (LM2738X). These high frequencies ...
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V – V > 2.5V for best performance. BOOST SW When the LM2738 starts up, internal circuitry from the BOOST pin supplies a maximum of 20mA to C current charges voltage sufficient to turn the ...
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For example, using the X-version let 0.7V 1mA, and duty cycle D = 50%. Then D2 ZENER I = 0.56 x (0.5 + 0.54 0. 2.5mA BOOST R3 = (10V ...
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... ESL. For MLCCs it is recommended to use X7R or X5R type capacitors due to their tolerance and temperature characteristics. Con- sult capacitor manufacturer datasheets to see how rated capacitance varies over operating conditions. OUTPUT CAPACITOR The output capacitor is selected based upon the desired out- put ripple and transient response ...
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The remaining components should also be placed as close as possible to the IC. Please see Application Note AN-1229 for further considerations and the LM2738 de- mo board as an example of a four-layer layout. RECOMMENED OPERATING AREA ...
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Calculating Efficiency, and Junction Temperature The complete LM2738 DC/DC converter efficiency can be calculated in the following manner. Or Calculations for determining the most significant power loss- es are shown below. Other losses totaling less than 2% are not discussed. ...
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Thermal impedance is defined as: Thermal impedance from the silicon junction to the ambient air is defined as: The PCB size, weight of copper used to route traces and ground plane, and number of layers within the PCB can great- ...
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FIGURE 9. 8-Lead LLP PCB Dog Bone Layout 30049179 15 www.national.com ...
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LM2738X Circuit Example 1 Part ID Part Value U1 1.5A Buck Regulator C1, Input Cap 10µF, 6.3V, X5R C2, Output Cap 22µF, 6.3V, X5R C3, Boost Cap 0.1uF, 16V, X7R D1, Catch Diode 0.34V D2, Boost Diode 1V L1 2.2µH, ...
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LM2738X Circuit Example 2 Part ID Part Value U1 1.5A Buck Regulator C1, Input Cap 10µF, 25V, X7R C2, Output Cap 33µF, 6.3V, X5R C3, Boost Cap 0.1µF, 16V, X7R D1, Catch Diode 0.34V F D2, Boost Diode 1V @ ...
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LM2738X Circuit Example 3 Part ID Part Value U1 1.5A Buck Regulator C1, Input Cap 10µF, 25V, X7R C2, Output Cap 47µF, 6.3V, X5R C3, Boost Cap 0.1µF, 16V, X7R C4, Shunt Cap 0.1µF, 6.3V, X5R D1, Catch Diode 0.34V ...
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LM2738X Circuit Example 4 Part ID Part Value U1 1.5A Buck Regulator C1, Input Cap 10µF, 25V, X7R C2, Output Cap 47µF, 6.3V, X5R C3, Boost Cap 0.1µF, 16V, X7R D1, Catch Diode 0.34V F D2, Boost Diode 1V @ ...
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LM2738X Circuit Example 5 Part ID Part Value U1 1.5A Buck Regulator C1, Input Cap 10µF, 25V, X7R C2, Output Cap 22µF, 16V, X5R C3, Boost Cap 0.1µF, 16V, X7R D1, Catch Diode 0.34V D2, Boost Diode 1V D3, Zener ...
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LM2738Y Circuit Example 6 Part ID Part Value U1 1.5A Buck Regulator C1, Input Cap 10µF, 6.3V, X5R C2, Output Cap 47µF, 6.3V, X5R C3, Boost Cap 0.1µF, 16V, X7R D1, Catch Diode 0.34V F D2, Boost Diode 1V @ ...
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LM2738Y Circuit Example 7 Part ID Part Value U1 1.5A Buck Regulator C1, Input Cap 10µF, 25V, X7R C2, Output Cap 47µF, 6.3V, X5R C3, Boost Cap 0.1µF, 16V, X7R D1, Catch Diode 0.34V D2, Boost Diode 1V L1 12µH, ...
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LM2738Y Circuit Example 8 Part ID Part Value U1 1.5A Buck Regulator C1, Input Cap 10µF, 25V, X7R C2, Output Cap (47µF, 6.3V, X5R 94µF C3, Boost Cap 0.1µF, 16V, X7R C4, Shunt Cap 0.1µF, 6.3V, X5R ...
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LM2738Y Circuit Example 9 Part ID Part Value U1 1.5A Buck Regulator C1, Input Cap 10µF, 25V, X7R C2, Output Cap (47µF, 6.3V, X5R 94µF C3, Boost Cap 0.1µF, 16V, X7R D1, Catch Diode 0.34V D2, Boost ...
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LM2738Y Circuit Example 10 Part ID Part Value U1 1.5A Buck Regulator C1, Input Cap 10µF, 25V, X7R C2, Output Cap 22µF, 16V, X5R C3, Boost Cap 0.1µF, 16V, X7R D1, Catch Diode 0.34V F D2, Boost Diode 1V @ ...
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Physical Dimensions www.national.com inches (millimeters) unless otherwise noted 8-Lead LLP Package NS Package Number SDA08A 8-Lead eMSOP Package NS Package Number MUY08A 26 ...
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Notes 27 www.national.com ...
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