TPA6211T-Q1: Shutdown time from operation mode

NOBUO FUJIHARA

Expert 8265 points

Part Number: TPA6211T-Q1

Hi team,

My customer built prototype for 2022 cluster and having an issue of pop nose when IGN_off (power off the system) .

When turn of IGN, MCU stops audio input to TPA6211 and sets SHUTDONW=Low.

In case SHUTDOWN timing and terminating audio input is close, pop noise appear.

In Figure 27, start-up time vs bypass capacitor is described.

Customer requires same kind of figure, shutdown time vs bypass capacitor, if shutdown time depends on bypass cap.

Can you support this request.

best regards,

over 2 years ago

0 Ivan Salazar over 2 years ago

TI__Guru* 95225 points

Hi Fujihara-san,

Perhaps adding some resistors could help on discharge time during power down, although this would cuase some increase in idle power consumption.
I can help getting some discharge time for different values of bypass capacitors, does customer have any specific values they want to evaluate?

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

0 NOBUO FUJIHARA over 2 years ago in reply to Ivan Salazar

TI__Expert 8265 points

Hi Ivan-san,

Thanks a lot for the support.

Customer especially want TI to evaluate 100us as shutdown time for system level target, and also requires shutdown time vs bypass cap figure.

Thanks and best regards,

0 Ivan Salazar over 2 years ago in reply to NOBUO FUJIHARA

TI__Guru* 95225 points

Fujihara-san,

Thanks for the details. I was asking more related ot the bypass capacitor value, but I understand they're looking for this time window for shutdown.
I'll plan to test this and let you know the results by next week.

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

0 NOBUO FUJIHARA over 2 years ago in reply to Ivan Salazar

TI__Expert 8265 points

Hi Ivan-san,

Can you provide results if it's ready?

best regards,

Nobuo

0 Ivan Salazar over 2 years ago in reply to NOBUO FUJIHARA

TI__Guru* 95225 points

Hi Fujihara-san,

I was not able to complete these tests and got pulled to other priorities, I'll revisit it this week and provide the results.

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

0 NOBUO FUJIHARA over 2 years ago in reply to Ivan Salazar

TI__Expert 8265 points

Hi Ivan-san,

My customer asks update.

Could you provide measurement results?

best regards,

0 Ivan Salazar over 2 years ago in reply to NOBUO FUJIHARA

TI__Guru* 95225 points

HI Fujihara-san,

I'm sharing my results today, will update shortly.

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

+1 Ivan Salazar over 2 years ago in reply to Ivan Salazar

TI__Guru* 95225 points

Fujihara-san,

My tests on the power down time for different Bypass capacitors suggest a couple things:

Power down time is very similar to power up time, it's basically the same charge/discharge rate
The time vs capacitance dependency is almost linear

Cbypass(uF)	Time(ms)
0	8
0.1	25
0.22	45
0.33	55
0.47	65
0.68	75
1	95
2.2	105

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

0 NOBUO FUJIHARA over 2 years ago in reply to Ivan Salazar

TI__Expert 8265 points

Thanks for your support.

Best regards,

Audio

Audio forum

TPA6211T-Q1: Shutdown time from operation mode