TPA2026D2: Input Impedance under Shutdown Mode

Koshi Ninomiya

Part Number: TPA2026D2
Other Parts Discussed in Thread: LM4810, TS5A23159, TS5A22364

Dear Team,

Could you let me know the inpur impedance under shutdown mode of TPA2026D2?

My customer is thinking to use Speaker Amp TPA2026D2 and Headphone Amp LM4810 in parallel at Audio DAC line out. There is a case that a SPDT analog switch is used to do audio signal routing. However, if input impedance under shutdown of speaker amp is Hi-Z, it could be not necessary to use the SPDT analog switch, they think.
Could you also let me know the suitable application between the Audio DAC line out and the inputs of Speaker Amp and Headphone Amp in parallel?
Thank you.

Best Regards,

Koshi Ninomiya

over 7 years ago

0 Ivan Salazar over 7 years ago

TI__Guru** 102045 points

Hi Ninomiya-san,

I'll work with one of my colleagues to see if we can get this value.
I'll come back to you with more details soon.

Best regards,
-Ivan Salazar
Audio Applications Engineer - Low Power Audio and Actuators

0 Koshi Ninomiya over 7 years ago in reply to Ivan Salazar

TI__Expert 4510 points

Hi Ivan-san,

I look forward to your reply.

If use a SPDT Analog SW, attached idea of stereo audio application is OK? If you have any suggestions, please let me know.
Thank you.

Best Regars,

Koshi Ninomiya

Stereo Audio Application.xlsx

0 José Luis over 7 years ago in reply to Koshi Ninomiya

TI__Mastermind 20085 points

Hi Ninomiya-san,

The input impedance is approximately 270 kΩ under shutdown mode.
The stereo audio application seems to be right, you can use an SPDT analog SW.

Best Regards
José Luis Figueroa
Audio Applications Engineer

0 Koshi Ninomiya over 7 years ago in reply to José Luis

TI__Expert 4510 points

Hi Jose-san,

Could I have your advice regarding the SPDT analog SW selection?

There are two SPDT analog SW. One is TS5A23159 (Simple function, but lower price), and the other is TS5A22364 (Internal Shunt Switch Prevents Audible Click-and-Pop When Switching Between Two Sources, but higher price). The customer want to avoide the Pop noise, but request lower application cost. The shunt switch is effective to avoid the pop noise in this application? Which one should we take?
Thank you.

Best Regards,

Koshi Ninomiya

5700.Stereo Audio Application.xlsx

0 José Luis over 7 years ago in reply to Koshi Ninomiya

TI__Mastermind 20085 points

Hi Ninomiya-san,

You should pick the TS5A22364 if the priority is to avoid the pop noise.
On the other hand, you can prove the TS5A23159 and check if the pop noise with this analog switch is acceptable to the customer.

Best Regards
José Luis Figueroa
Audio Applications Engineer

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TPA2026D2: Input Impedance under Shutdown Mode