LM3401-MR16DEMO/NOPB National Semiconductor, LM3401-MR16DEMO/NOPB Datasheet
LM3401-MR16DEMO/NOPB
Specifications of LM3401-MR16DEMO/NOPB
Related parts for LM3401-MR16DEMO/NOPB
LM3401-MR16DEMO/NOPB Summary of contents
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... Hysteretic PFET Controller for High Power LED Drive General Description The LM3401 is a switching controller designed to provide constant current to high power LEDs. The LM3401 drives an external P-MOSFET switch for step-down (Buck) regulators. The LM3401 delivers constant current within ±6% accuracy to a wide variety and number of series connected LEDs. Out- put current is adjusted with an external current sensing resis- tor to drive high power LEDs in excess of 1A ...
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... Connection Diagram Ordering Information Part Number Package Type LM3401MM MSOP-8 LM3401MMX Pin Descriptions Pin # Pin Name 1 CS Current sense pin. Connect to the PFET drain 2 DIM Dimming input pin. When DIM is low, the HG drive is off. Can be connected to a logic level PWM signal ...
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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 CS SNS ILIM DIM HYS Storage Temperature Electrical Characteristics apply over the junction temperature (T limits are guaranteed through test, design, or statistical correlation. Typical values represent the most likely parametric norm 25° ...
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Typical Performance Characteristics V vs Temperature REF HYS Multiplier vs Temperature ILIM Sink Current vs Temperature www.national.com Unless otherwise specified, V HYS Current vs V 30021403 Startup Waveforms 30021406 HYS Current vs Temperature 30021408 4 = 24V 25°C. ...
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UVLO Threshold vs Temperature 30021410 Line Transient Response 30021457 350 mA Efficiency 30021458 SNS to HG Propagation Delay vs V Initial HG Voltage vs Input Voltage 700 mA and 1A Efficiency 5 IN 30021455 30021414 30021459 www.national.com ...
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... Block Diagram Operational Description HYSTERETIC CONTROL The LM3401 is a step-down DC-DC controller designed to provide a constant current source for driving a high power LED string. The LM3401 uses comparator-based voltage mode hysteretic control for a simple and stable design. Hysteretic control does not utilize an internal oscillator, but relies on output conditions to directly control switching ...
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... LED forward voltages, and ANODE delay is the sum of the LM3401 propagation delay time and the PFET delay time. The LM3401 propagation delay typically (See the Propagation Delay curve). Alternately, the inductor value can be calculated from a known frequency by ...
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... This value should be used to determine the LED_RIP peak current shown in the Output Current Setting LED_PK section. Since the LM3401 can operate at 100% duty cycle, the in- ductor must be rated to handle I LED_PK www.national.com RIPPLE REDUCTION CAPACITOR The typical application schematic shown on the front page is the simplest application of the LM3401 ...
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... DS(on) value at 25°C. The Gate capacitance of the PFET has a direct impact on both PFET transition time and the power dissipation in the LM3401. Most of the power dissipated in the LM3401 is used to drive the PFET switch. This power can be calcu- lated as follows: The average amount of gate driver current required during (off state ...
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... When pulled low, DIM will disable HG and switching will stop. The PFET will remain off as long as DIM is low. When the LM3401 is powered up or enabled with the DIM pin, the LED current will very rapidly increase to its set point. There is minimal delay time between a DIM logic change and HG switching ...
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... LED CURRENT ACCURACY The total accuracy of average LED current is affected by sev- eral factors, both internal and external to the LM3401. Total static accuracy is the part-to-part variation and can be calcu- lated from the equation below: Where the worst case V is ± ...
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The SNS and HYS resistors should be placed close to their respective pins and grounded close to the GND pin. An iso- lated ground area shown as SGND in Figure 10 is recom- mended for the SNS, HYS, and GND ...
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Design Example The following design example is intended to illustrate the step-by-step design process described in the previous sec- tions. The example refers to the circuit in Figure 11, and the results are summaized in Table 1. The resulting circuit ...
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This confirms that the component selections will keep LED peak current below the maximum LED rating. Notice if a ripple reduction capacitor is chosen, the peak inductor current is still 804mA, but the LED peak current is reduced. Therefore, the ...
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This is the estimated amount of LED current variation over the input voltage range. If the minimum input voltage was below Parameter Value R1 290 mΩ R2 5.6 kΩ µH, >804 ripple ...
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Physical Dimensions www.national.com inches (millimeters) unless otherwise noted 8-Lead MSOP Package NS Package Number MUA08A 16 ...
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Notes 17 www.national.com ...
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