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NCP5252 Circuit Design Aid Calculator Excel Spread Sheet Calculator

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NCP5252 Circuit Design Aid Calculator Excel Spreadsheet

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Download: NCP5252 Circuit Design Aid

The NCP5252 is a fast-transient-response and high-efficiency single-phase buck regulator with built-in MOSFETs. This Excel spreadsheet is a design aid for applications with the NCP5252. There are two functions provided by this design aid. The first function is to come up with a recommended solution after the user inputs an application spec; The second function is to work out calculation results based on user's real application solution and operation condition.

How to use?
1. Application Spec Input (Sheet "Summary")

  1. Input supply nominal voltage (Cell "E14") and range (Cell "E16" and "E17"). The range is within 4.5V ~ 13.2V.
  2. Input nominal switching frequency (Cell "E15").
  3. Output voltage nominal values (Cell "D23").
  4. Output current noninal values (Cell "D31"), and over current ratio numbers (Cell "D32").
  5. Inductor current ripple spec (Cell "D48") and output voltage ripple/transient spec (Cell "D50:D54").
  6. Load transient current spec (Cell "D59:D62").
  7. Ambient temperature in Cell "E66".

2. Component Selection (Sheet "Summary")

  1. Select inductors according to recommended values (Cell "D106"), and input information of the selected inductors in Cell "E106:E108".
  2. Select output capacitors according to recommended total capacitance (Cell "D109") and effecitive ESR (Cell "D110"), and input information of the selected capacitors in Cell "E109:E110".
  3. Input feedback resistance in Cell "E124", and then select feedback and compensation components in Cell "E125:E130" according to recommended parameters in Cell "D125:D130".
  4. Input snubbers (if used) in Cell "D93:D94".
  5. Input on-board BST resistance (if used) in Cell "E98".

3. Review Calculation Results (Sheet "Summary", "Compensation", and "Loss & Efficiency")

  1. Review inductor current ripple, output ripple, and transient performance in Sheet "Summary".
  2. Input loading current in Cell "E31" of Sheet "Summary" to review loss and efficiency under this loading condition.
  3. Review output regulation and close-loop gain/phase in Sheet "Compensation".
  4. After set ambient temperature in Cell "E66" of Sheet "Summary", make the predicted temperatures (Cell "C72:E72") of the components to be close to the calculated results (Cell "C71:E71" in Sheet "Summary") in order to improve calculation accuracy.
  5. Review power losses, temperatures, and efficiency details in Sheet "Loss & Efficiency".

4. Fine Tune Solution (Sheet "Summary")

  • Optimize solution by repeating action Item 2 and Item 3.

5. Record Design (Sheet "Summary")