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LM5157: About the characteristics (Line Regulation) of LM5157

Part Number: LM5157
Other Parts Discussed in Thread: TPS54680, ,

① Please tell me the electrical characteristics and measurement conditions of Line Regulation.

 *There is no description in the data sheet.

② Please also include an example of line regulation calculations.

Example (line regulation characteristics)

  • Hello Minoru,
    Thanks for reaching out to us via e2e.

    May I kindly ask you to properly enter your name in the system? Currently you show up as user6448843.

    There is no equation to calculate the line regulation.
    These diagrams have been derived from measurements on real boards.

    This characteristic is not defined by the controller device itself, but by the whole circuitry, including the compensation network and all other external components.
    So, in the end it is just one particular example.
    The TPS54680 datasheet includes many such application examples whereas the LM5157 datasheet does not.

    You can find an example for the reaction on an input transient of an LM5157 based board in the user's guide of the LM5157-Q1 Flyback EVM, figure 6-22 and 6-23:

    Best regards

    All information in this correspondence and in any related correspondence is provided “AS IS” and “with all faults” and is subject to TI’s Important Notice (