lm25011myx National Semiconductor Corporation, lm25011myx Datasheet
lm25011myx
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lm25011myx Summary of contents
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... Additional features include: Low output ripple, VIN un- der-voltage lock-out, adjustable soft-start timing, thermal shutdown, gate drive pre-charge, gate drive under-voltage lock-out, and maximum duty cycle limit. Typical Application, Basic Step-Down Regulator © 2009 National Semiconductor Corporation LM25011 Features ■ Input operating voltage range 42V ■ ...
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... Connection Diagram Ordering Information Order Number Package Type LM25011MY MSOP-10EP LM25011MYX MSOP-10EP Pin Descriptions Pin No. Name Description 1 VIN Input supply voltage 2 RT On-time Control 3 PGD Power Good 4 SS Soft-Start 5 SGND Signal Ground 6 FB Feedback 7 CSG Current Sense Ground 8 CS Current sense ...
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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 SGND (T = 25°C) J BST to SGND SW to SGND (Steady State) BST ...
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Symbol Parameter Power Good (PGD pin) Threshold at FB, with respect to V Threshold hysteresis PGD Low state voltage VOL PGD Off state leakage LKG Thermal Shutdown T Thermal shutdown SD Thermal shutdown hysteresis Thermal Resistance θJA Junction to Ambient, ...
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Typical Performance Characteristics Efficiency (Circuit of Figure 5) On-Time vs V and R IN Shutdown Current into VIN 30094603 T 30094605 Operating Current into VIN 30094607 5 Efficiency at 2 MHz 30094604 Voltage at the RT Pin 30094606 30094608 www.national.com ...
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PGD Low Voltage vs. Sink Current Current Limit Threshold vs. Temperature VIN UVLO vs. Temperature www.national.com Reference Voltage vs. Temperature 30094609 Operating Current vs. Temperature 30094611 SS Pin ShutdownThreshold vs. Temperature 30094613 6 30094610 30094612 30094614 ...
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On-Time vs. Temperature 30094615 Minimum Off-Time vs. Temperature 7 30094616 www.national.com ...
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Block Diagram www.national.com 8 ...
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Functional Description The LM25011 Constant On-time Step-down Switching Reg- ulator features all the functions needed to implement a low cost, efficient buck bias power converter capable of supplying up to 2.0A to the load. This high voltage regulator contains an ...
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The approximate operating frequency is calculated as follows: The buck switch duty cycle is approximately equal to: When the load current is less than one half the inductor’s rip- ple current amplitude the circuit operates in discontinuous conduction mode. ...
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Ripple Requirements The LM25011 requires a minimum of 10 mVp-p ripple voltage at the CS pin. That ripple voltage is generated by the de- creasing recirculating current (the inductor’s ripple current) through R during the off-time. See Figure 3. S ...
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FIGURE 4. Shutdown Implemetation Power Good Output (PGD) The Power Good output (PGD) indicates when the voltage at the FB pin is close to the internal 2.51V reference voltage. The rising threshold at the FB pin for the PGD output ...
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Current limit detection occurs when the voltage across the sense resistor (R ) reaches the current limit threshold. To al- S low for tolerances, the sense resistor value is calculated using the minimum threshold specification 115 mV/1.4A = ...
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FIGURE 6. Efficiency (Circuit of Figure 5) FIGURE 7. Frequency vs V (Circuit of Figure 5) IN www.national.com FIGURE 5. Example Circuit PC BOARD LAYOUT The LM25011 regulation and current limit comparators are very fast, and respond to short duration ...
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Physical Dimensions inches (millimeters) unless otherwise noted 10-Lead MSSOP-EP Package NS Package Number MUC10A 15 www.national.com ...
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... National Semiconductor and the National Semiconductor logo are registered trademarks of National Semiconductor Corporation. All other brand or product names may be trademarks or registered trademarks of their respective holders. ...