Hi Sir,
I am currently using the TPS43060EVM-199 to simulate a design with the following parameters:
Input: 12V @ 12A
Output: 20V @ 7.12A
I have modified the components on the EVM based on the recommended values from the simulation Excel tool. However, I am encountering an issue where the output voltage ripple (Vout peak-to-peak) reaches up to 3.8V under full load, as shown in the attached test results.
In addition, I have tested different switching frequencies (294kHz, 500kHz, and 750kHz) and inductor values (3.3µH to 10µH). All inductors used have an Isat of at least 15.5A. Despite these adjustments, the ripple under a 7.5A load remains relatively high (please refer to the attached screenshot).
I also conducted further experiments by varying the capacitance and inductance at the same frequency. Here is a summary of my findings:
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Starting with 5 × 22 µF MLCCs and one 330 µF electrolytic capacitor (totaling 440 µF), increasing the MLCCs to 10 pcs (totaling 550 µF) significantly improves the Vout peak-to-peak ripple.
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Increasing the number of MLCCs to 10 pcs (totaling 550 µF) noticeably improves the Vout peak-to-peak ripple.
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However, adding an additional 330 µF electrolytic capacitor on top of this configuration does not result in significant further improvement.
The best performing configuration so far is:
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Capacitors: 22 µF / 35V / 0805 / X5R × 10 pcs + 330 µF / 35V electrolytic capacitor (Total: 550 µF)
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Inductor: 4.7 µH
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Frequency: 750 kHz
I would like to ask the following questions:
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According to the simulation, the expected ripple should be around 200mV, but it took extensive component adjustments and testing to finally reach 248mV. Normally, I would expect the peak-to-peak ripple at 20V output to fall within the 100mV to 200mV range. Is there a specific reason why it requires so much tuning to get close to the expected performance?
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Do you have any recommendations for frequency selection? Specifically, would using 500kHz or even 750kHz introduce any potential drawbacks or limitations for the TPS43060?
Please refer to the attached schematic and test result table for more details. I would greatly appreciate any insights or suggestions you can provide.
複本 TPS4306x_BOOST_CALCTOOL_REVB_250509.xlsTPS43060 Vout noise test& HDRV frequency_250513.xlsx
