Frequent Questions

  • [FAQ] LMx518x: What are the different products in LMx518x family and how they differ?

    Part Number: LM5180-Q1 Other Parts Discussed in Thread: LM25180 , LM5180 , LM25185 , LM5185 , LM5181 , LM25183 , LM25184 If you are going for PSR Flyback topology for power requirement of 1W to 50W, you can take these LMx518x devices into your design…

  • [FAQ] LMx518x: What are design considerations for Flyback transformer?

    Flyback transformers play a crucial role in Flyback topology design, Flyback topology requires coupled inductors with proper turns ratio, better magnetizing inductance and minimum leakage. Turns Ratio: Turns ratio must be selected considering recommended…

  • [FAQ] LMx518x: What is the maximum output power deliverable?

    Other Parts Discussed in Thread: LM5181 , LM25180 For converter parts (LM5181/0, LM25180/3/4), to calculate maximum output power, you can use these formulae: POWER DELIVERY CURVES Pout vs Vin for all variants on same graph at different turns ratio…

  • [FAQ] LMx518x: How to select Snubber circuits?

    Snubber circuits are designed to suppress voltage spikes, limit the rate of voltage and current changes, and protect switching devices from damage. It is recommended to use snubber circuits across SW and Vin, and across Flyback diode. Refer this technical…

  • [FAQ] LMx518x: Why is my output voltage not as expected/calculated?

    Part Number: LM5180-Q1 Flyback transformer To operate as flyback converter, transformer polarity has to be as expected, reversing polarity makes the converter work as forward converter which cannot provide expected output when loaded. Also, check…

  • [FAQ] LMx518x: How to select RSET, RFB, RTC?

    RSET resistor is used to set the internal 1.21-V reference to the input of the error amplifier for internal closed loop. RSET is recommended to keep at 12.1 Kohm to maintain 100uA current in RFB and RSET resistors, and vary RFB to obtain required output…

  • [FAQ] LMx518x: How to select Flyback Diode?

    Select a Schottky diode for this application to account for inevitable diode voltage overshoot and ringing related to the resonance of transformer leakage inductance and diode parasitic capacitance. Connect an appropriate RC snubber circuit (for example…

  • [FAQ] LMx518x: How to select Zener Clamp on transformer primary side?

    Other Parts Discussed in Thread: LM25184 Connect a diode-Zener clamp circuit across the primary winding to limit the peak switch voltage after MOSFET turnoff. We recommend using a Zener diode with a clamp voltage of ~1.5x the reflected output voltage…

  • [FAQ] AM263P4-Q1: How to parse AM263P ROM Logs

    Part Number: AM263P4-Q1 Hi expert, Can you provide me the steps or tools necessary to parse ROM Logs in AM263P SoC.

  • [FAQ] LM5180/1, LM25180/3/4 FAQs

    Other Parts Discussed in Thread: LM25180 , LM5180 , LM25185 , LM25184 , LM25183 , LM5185 , LM5181 LM5180/1, LM25180/3/4 FAQs Home Page This home page is for common questions in relation to the LM5180, LM5181, LM25180, LM25183, LM25184, LM25185, LM5185…

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