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NCP5252 Circuit Design Aid Calculator Excel Spread Sheet Calculator
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")
- Input supply nominal voltage (Cell "E14") and range (Cell "E16" and "E17"). The range is within 4.5V ~ 13.2V.
- Input nominal switching frequency (Cell "E15").
- Output voltage nominal values (Cell "D23").
- Output current noninal values (Cell "D31"), and over current ratio numbers (Cell "D32").
- Inductor current ripple spec (Cell "D48") and output voltage ripple/transient spec (Cell "D50:D54").
- Load transient current spec (Cell "D59:D62").
- Ambient temperature in Cell "E66".
2. Component Selection (Sheet "Summary")
- Select inductors according to recommended values (Cell "D106"), and input information of the selected inductors in Cell "E106:E108".
- 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".
- 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".
- Input snubbers (if used) in Cell "D93:D94".
- Input on-board BST resistance (if used) in Cell "E98".
3. Review Calculation Results (Sheet "Summary", "Compensation", and "Loss & Efficiency")
- Review inductor current ripple, output ripple, and transient performance in Sheet "Summary".
- Input loading current in Cell "E31" of Sheet "Summary" to review loss and efficiency under this loading condition.
- Review output regulation and close-loop gain/phase in Sheet "Compensation".
- 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.
- 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")