Switching frequency for the TPA3106D1

Eric Musser

Other Parts Discussed in Thread: TPA3106D1

Hello

I'm using the TPA3106D1 in a Master/Slave setup for a stereo configuration and I have 2 questions.

1. If I'm using hard set resistors to set the Gain inputs, can I use the Vreg from one amp as the power supply for these resistors which will set the gains for both amps? Or should I have separate gain resistors for on each amp chip, using their individual Vreg supplies?

2. Refering to the switiching frequency set by ROSC, does it become unstable if ran outside of the 200-300 khz window as sugguested in the data sheet? Also, why does the ROSC resistor have to be populated on the slave amp, and does the value matter for the slave amp?

Thanks

over 14 years ago

0 user5276421 over 14 years ago

TI__Mastermind 37045 points

Hi Eric,

The ROSC is still required in SLAVE mode and we can't guarantee proper operation outside the d/s range. It would be ok to use one VREG and the same resistors for the gain setting but you need to keep the external current draw from VREG to less than 5mA since VREG is also used to bias the internal circuitry.

reg,

Paul C. Chen

Audio Applications Engineer

Dallas TX USA.

0 Eric Musser over 14 years ago in reply to user5276421

Prodigy 30 points

Thanks for the information on the ROSC. I do want to mention as far as the gain resistors being used for both amps, will it be a problem if I'm only powering up one amp (ie mono mode) at certain times?

Thanks

0 Don Dapkus over 14 years ago in reply to Eric Musser

TI__Guru**** 189401 points

Eric,

Maybe... Check out this app note:

http://focus.ti.com/general/docs/litabsmultiplefilelist.tsp?literatureNumber=sloa130

It depends on what you mean by "powering up." If you put one in SD, but still drive the G0/1 pins high, then yes, it will be a problem.

If you plan on removing the power from the second device (like a swithced LDO or something) then you run the risk of forward-biasing the ESD cell on the G0/1 pins. I would recommend two sets of gain-setting resistors to be on the safe side.

-d2

Audio

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Switching frequency for the TPA3106D1