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TPA3110D2 Inductor selection
I am using TPA3110D2 with 4 ohm load and trying to size the output inductor and capacitor. As shown in the attached pics the datasheet says the inductor should be 33uh for 4 ohm load with 0.68uf capacitor where as the reference schematic uses 22uh inductor with 0.68uf capacitor. Is the lower value inductor (22uh) in the reference schematic due to ferrite bead also being present in parallel? From the attached supply current graph the max current with 4 ohms load will not be more than 2A. Will inductor of 3A rating sufficient? What is the recommended indcutance and current rating for use with 4 ohms load? also the value of the cap. Our application doesn't require EMI qualification so not planning to add EMI filtering components.
Sec 1.1 of the EVM user guide says "Load Impedance Stereo BTL - 4 to 8 Ω (connect 33-mH series inductor for 4 Ω or 68-mH inductor for 8 Ω if using the ferrite bead
filters)". Is it mH or uH?
Please refer to the apps report SLOA119A for LC filter selection. TPA3110D2 uses BD modulation. Inductors should be uH and not mH. At higher currents an inductor's core saturates, it's inductance falls. You would have to review inductor manufacturer's datahseet for I.sat to ensure that the inductor is able to maintain enough inductance at peak current.
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