TAS5142: How to calculate audio gain from digital amplifier

Jonathan Lee89

Part Number: TAS5142
Other Parts Discussed in Thread: TAS5558

Hello TI.

This is Jonathan from Avnet.

One of major customers is developing AVR system by using TI's TAS5142 as can be seen below block diagram.

The customer would like to calculate audio gain from TAS5142 but they can't find any information about how to calculate audio gain on the data sheet.

I would appreciate it if you could let me know how to calculate audio gain from the TAS5142.

Thanks.

TAS5142 PVDD = 29V

TAS5558 DVDD = 3.3V

over 6 years ago

0 Adam Sidelsky over 6 years ago

TI__Guru 61360 points

Jonathan,

Because this is a PWM input device we cannot simply calculate Vout/Vin and get the gain. The datasheet number comes from design and is the combination of all the internal stages of the different blocks in the device. Is there a reason the customer wants to calculate this themselves?

Regards,

-Adam

0 Jonathan Lee89 over 6 years ago in reply to Adam Sidelsky

Intellectual 380 points

Dear Adam.

Our customer is doing business with D&M(Denon) and they are getting ready for drawing up gain-diagram in accordance with Denon's request.

That's why the customer want to know audio gain from TAS5142. Please refer to customer's gain-diagram as example below.

Could you let me know approximately audio gain value from TAS5142 ?

Jonathan.

0 Adam Sidelsky over 6 years ago in reply to Jonathan Lee89

TI__Guru 61360 points

Jonathan,

This device is open loop and therefore the Gain is PVDD/VREG. Assuming a typical 32V PVDD, and VREG of 3.3V, the gain is 32/3.3 or 9.7 which comes out to about 19.7dB.

Regards,

-Adam

0 Jonathan Lee89 over 6 years ago in reply to Adam Sidelsky

Intellectual 380 points

Adam.

This solved my issue.
Thanks for your effort.

Jonathan.

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TAS5142: How to calculate audio gain from digital amplifier