TPA3244: how to reduce the precharge time of VIN_X

Jeffrey

Expert 1920 points

Part Number: TPA3244
Other Parts Discussed in Thread: TPA3220

Dear community members,

There is a problem that initial sound is cut when music is played.

I think that it is occurred due to long precharge time of VIN_X after high /RESET.

So, I want to know how to reduce the precharge time of about 200ms like below picture.

Please let me know this solution.

Regards,

Jeffrey

over 6 years ago

0 Matthew Miao over 6 years ago

TI__Expert 6720 points

H Jeffrey,

The 200ms pre-charge is the typical value to stabilize the DC voltage across the input AC coupling capacitors, before the ramp up sequence starts. It is decided by input DC decoupling cap and input impedance.

Robert will follow up TPA3244 related issue soon.

Rgs,
Matthew

0 Robert Clifton56 over 6 years ago in reply to Matthew Miao

TI__Mastermind 28130 points

Hi Jeffery,

Matthew is correct. The pre-charge time is internally set to charge the expected 10uF AC coupling capacitors so there's no way to adjust this pre-charge time.

Best Regards,
Robert Clifton

0 Jeffrey over 6 years ago in reply to Robert Clifton56

Expert 1920 points

Hi Robert,

To adjust the pre-charge time, I want to try the input ac coupling capacitor's value change from 10uF to 1~10uF(less than 10uF).
Is it ok or any problems?

Regards,
Jeffrey

0 Robert Clifton56 over 6 years ago in reply to Jeffrey

TI__Mastermind 28130 points

Hi Jeffery,

The pre-charge time is internally set in the device. The device expects to see a 10uF not a 1uF. However if pre-charge time is a critical spec in your system, you can look at the TPA3220. This device has similar specs to the TPA3244 but it has a quicker pre-charge time since the input ac coupling capacitor was optimized for 1uF. There are of course other differences between the TPA3244 and the TPA3220 but I'd recommend taking a look at it.

Best Regards,

Robert Clifton

0 Jeffrey over 6 years ago in reply to Robert Clifton56

Expert 1920 points

Hi Robert,

Thanks for your reply.
I'll take a look at TPA3220 you recommend.

Regards,
Jeffrey

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TPA3244: how to reduce the precharge time of VIN_X