LM4675 driving headphone question.

peter zhu2

Other Parts Discussed in Thread: LM4675, TPA6132A2, TPA2051D3

Hi, Expert:

In one of my project, LM4675 is used for drive speaker, and it also needs to support headphone. Can i use LM4675 to drive headphone? I am not sure about this, because the datasheet only mentions speaker.

Thanks

Peter

over 13 years ago

0 peter zhu2 over 13 years ago

Prodigy 60 points

any feedback? Peter

0 Don Dapkus over 13 years ago in reply to peter zhu2

TI__Guru**** 189401 points

Hi, Peter,

LM4675 uses BD modulation which is only compatible with BTL (Bridge-Tied Load).

You have two choices:

1. Add something like a TPA6132A2 HP amp to your circuit, or

2. Use something like TPA2051D3 which has an integrated mono class-D amplifier, and stereo HP amplifier.

-d2

0 peter zhu2 over 13 years ago in reply to Don Dapkus

Prodigy 60 points

Hi, Don:

Thanks for your support.

What will happen if connect a headphone to LM4675 output? I saw 4675 modulation is duty cycle change, is the amplitude fixed in VDD to GND?

Peter

0 peter zhu2 over 13 years ago in reply to peter zhu2

Prodigy 60 points

Don, what's the difference between the speaker and headphone? Can i think all speakers are BTL? I have thought headphone is also a speak, which has low volume.

Is there any white paper?

Peter

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LM4675 driving headphone question.