LM20333MH National Semiconductor, LM20333MH Datasheet
LM20333MH
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LM20333MH Summary of contents
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... The LM20333 is offered in an exposed pad 20-pin eTSSOP package that can be soldered to the PCB, eliminating the need for bulky heatsinks. Simplified Application Circuit ® PowerWise is a registered trademark of National Semiconductor Corporation. © 2008 National Semiconductor Corporation ® Synchronous Buck Regulator with Features ■ ...
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... Connection Diagram Ordering Information Order Number Package Type LM20333MH eTSSOP-20 LM20333MHE LM20333MHX Pin Descriptions Pin(s) Name Description 1 SS/TRK Soft-Start or Tracking control input 2 FB Feedback input to the error amplifier from the regulated output 3 PGOOD Power good output signal 4 COMP Output of the internal error amplifier and ...
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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 BOOT to GND BOOT GND SW to GND (Transient) FB, EN, SS/TRK, COMP, SYNC, PGOOD to GND Electrical Characteristics type are for T = 25°C only, limits in bold face type apply over the junction temperature (T J and maximum limits are guaranteed through test, design, or statistical correlation ...
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Symbol Parameter g Error Amplifier DC Transconductance m A Error Amplifier Voltage Gain VOL GBW Error Amplifier Gain-Bandwidth Product Current Limit I Cycle By Cycle Positive Current Limit LIM I Cycle By Cycle Negative Current Limit LIMNEG T Cycle By ...
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Efficiency vs. Load Current f = 750 kHz SW 30051685 Error Amplifier Phase 30051606 Load Regulation 30051686 Error Amplifier Gain Line Regulation V vs 30051605 30051607 30051608 www.national.com ...
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Non-Switching I PGOOD Output Low Level Voltage vs. I UVLO Threshold and Hysteresis vs. Temperature www.national.com vs 30051609 Enable Threshold and Hysteresis vs. Temperature PGOOD 30051619 30051695 6 Shutdown I vs 30051610 30051621 Enable ...
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Clock Synchronization Low-Side FET Resistance vs. Temperature Peak Current Limit vs. Temperature High-Side FET Resistance vs. Temperature 30051680 Load Transient Response 30051657 Startup with prebiased output 30051658 7 30051655 30051656 30051679 www.national.com ...
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Startup with C Startup with applied Track Signal www.national.com = 0 SS 30051659 30051681 8 Startup with C = 100 nF SS 30051660 ...
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Block Diagram 9 30051623 www.national.com ...
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Operation Description GENERAL The LM20333 switching regulator features all of the functions necessary to implement an efficient buck regulator using a minimum number of external components. This easy to use regulator features two integrated switches and is capable of supplying ...
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PGOOD pin has 20 µs of built in deglitch time to both rising and falling edges. UVLO The LM20333 has an internal under-voltage lockout protec- tion circuit that keeps the device from switching until the input voltage reaches ...
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Keep in mind ceramic capacitors are sometimes preferred because they have very low ESR; however, depending on package and voltage rating of the capacitor the value of the capacitance ...
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FIGURE 3. LM20333 Loop Compensation The power stage transfer function is dictated by the modula- tor, output LC filter, and load; while the feedback transfer function is set by the feedback resistor ratio, error amp gain and external compensation network. ...
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When the device is enabled there is an approximate time interval of 50 µs when the soft-start capac- itor will be discharged ...
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Similar to the soft-start function, the fastest start up possible is 1ms regardless of the rise time of the tracking voltage. When using the track feature the final voltage seen by the SS/ TRACK pin should exceed 1V to provide ...
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FIGURE 10. Safe Thermal Operating Areas ( 750kHz) SW FIGURE 11. Safe Thermal Operating Areas ( 500kHz) SW The dashed lines in the figures above show an approximation of the minimum and maximum duty cycle limitations; ...
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Voltage accuracy at the load is important so make sure feedback voltage sense is made at the load. Doing so will correct for voltage drops at the load and provide the best output accuracy. ...
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... Bill of Materials (V = 12V Qty Part Number U1 1 LM20333MH C1 1 C3225X5R1E226M C2 GRM21BR61E475KA12L C5 C1608X7R1H104K C4 1 C1608X5R1A105K C7 1 C1608C0G1H100J C8 1 C1608C0G1H152J C9 1 6TPB150MAZB D1 1 CMMSH1-40-NST L1 1 IHLP4040DZER5R6M01 R1 CRCW06031002F R2 1 CRCW06031502F R3 1 CRCW06033092F www.national.com FIGURE 14. Typical Application Schematic = 3.3V 3A, f OUT OUT Size eTSSOP-20 IC, Switching Regulator ...
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Physical Dimensions inches (millimeters) unless otherwise noted 20-Lead eTSSOP Package NS Package Number MXA20A 19 www.national.com ...
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