TPA3156D2: SFR of output LC filter

Mikhail Isagulov

Prodigy 120 points

Part Number: TPA3156D2

Hi. We are going to use D-class with load - piezo transponder. PWM of output is 1 MHz.

Questions is - what minimal SFR of inductor into output LC filter I can take?

In our case for "critically damped" I should take 180uH and best than I can find have SFR-3 MHz or less.

Unfortunately I can't find any about SFR into SLOA242A and slaa701a.

Regards.

over 2 years ago

0 Luis Fernandes de Pina over 2 years ago

TI__Genius 14420 points

Hello Mikhail,

There isn't really a device spec for this but you can use the https://www.ti.com/tool/LCFILTER-CALC-TOOL to assist you in designing your LC filter for our device outputs.

best regards,

Luis

0 Mikhail Isagulov over 2 years ago in reply to Luis Fernandes de Pina

Prodigy 120 points

Hello Luis,

TI have really wonderful documentation/app_note and calc-tool, but unfortunately no recommendation regarding SFR(Self Resonant Frequency) of inductor.

For 2,4,8 Ohm load it is far from PWM of D-class, but for 100 Ohm load ( inductance about 80-120 uH) it should be takin to attention.

Please advise.

+1 Luis Fernandes de Pina over 2 years ago in reply to Mikhail Isagulov

TI__Genius 14420 points

Hello Mikhail,

Typical applications for this device don't use these high impedances so we don't have recommendations on this spec.

best regards,

Luis

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TPA3156D2: SFR of output LC filter