TPA3137D2: Vout/Vin gain as compared to TPA3136D2

Christian Greeff

Part Number: TPA3137D2
Other Parts Discussed in Thread: TPA3136D2,

Greetings,

I have a customer looking to use the TPA3137D2 as a second source of the TPA3136D2. When testing the 3137, the output power (and therefore perceived volume output) seemed lower than that of the 3136 for this same input into the chip.

Is there any difference in the Vout/Vin gain of these parts?

This information will be helpful tuning the volume so that all of the products behave consistently.

Thanks,

Christian Greeff

over 3 years ago

0 Luis Fernandes de Pina over 3 years ago

TI__Genius 14480 points

Hello Christian,

THE TPA3137 spec is for 6W stereo, the TPA3136 spec is for 10W stereo so the lower output power is expected.

best regards,

Luis

0 Christian Greeff over 3 years ago in reply to Luis Fernandes de Pina

TI__Prodigy 530 points

Hi Luis,

Thank you for your response. Does this mean that the input of the TPA3137 should be scaled by a factor of 10/6 = 5/3 in order to match the power output of the TPA3136?

Thanks,

Christian

0 Luis Fernandes de Pina over 3 years ago in reply to Christian Greeff

TI__Genius 14480 points

Hello Christian,

It's not a factor of just scaling the input, the devices while extremely similar have some internal differences. If you go past 6W you could encounter thermal issues due to the limitations of the device this can be seen in our Output Power vs Supply Voltage(dashed line indicates a region of thermal instability). Both devices have a fixed gain but have a different max output power

TPA3137 does 2 x 6W into 8 ohm at 10% THD for a 13V PVDD

TPA3136 does 2 x 10W into 8 ohm at 10% THD for a 13V PVDD.

best regards,

Luis

0 Christian Greeff over 3 years ago in reply to Luis Fernandes de Pina

TI__Prodigy 530 points

Hi Luis,

In this case the Max output used is only 2W, the main concern here is the noticeable difference in the volume levels for a given volume setting between the two devices. The customer wants to account for this in software with the CODEC gain settings, but needs to know what the Vout/Vin gain difference is between these parts.

Thanks,

Christian

0 Luis Fernandes de Pina over 3 years ago in reply to Christian Greeff

TI__Genius 14480 points

Hello Christian,

let me check this info and verify on bench, this isn’t a typical parameter we have.

best regards,

luis

0 Christian Greeff over 3 years ago in reply to Luis Fernandes de Pina

TI__Prodigy 530 points

Hi Luis,

Excellent thank you for looking into this. I look forward to hearing what results you find.

Thanks,

Christian

0 Yanming Gong over 3 years ago in reply to Christian Greeff

TI__Mastermind 19340 points

Hello Christian,

The Rdson of TPA3136 and TPA3137 are same, so the output power should be same if on 2W output power condition.

Is there same PCB layout and other test condition is same?

Regards,

Derek

0 Christian Greeff over 3 years ago in reply to Yanming Gong

TI__Prodigy 530 points

Hi Derek,

The PCB layout and test conditions were the same in this case.

Thanks,

-Christian

+1 Luis Fernandes de Pina over 3 years ago in reply to Christian Greeff

TI__Genius 14480 points

Hello Christian

Closing this thread after our discussion on the phone.

Best regards,

Luis

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TPA3137D2: Vout/Vin gain as compared to TPA3136D2