TPA3139D2: TPA3139

Hi,

You can follow the description from data sheet section 7.3.3 (page 17).
For experimental purposes, you may use a potentiometer connected to PLIMIT pin and manually adjust this value until you get the desired output limiting.

Best regards,
-Ivan Salazar
Applications Engineer

ok

But Theoretically to fix a divider value without having the option of potentiometer 

VP​=5.7×VPLIMIT​(for BD Mode)

The power output formula is:

​

for a 2 watt 4 ohm speaker 

For Pout  2W, RL=4Ω, and assuming RS≈0.3Ω

VP​=4V×1.15=4.6V

VPLIMIT​=5.7VP​​=5.74.6V​=0.807V

VPLIMIT​=VCC​×R2​/(R1+R2)

Choosing R1=100kΩ 

R2=0.807V / 5V×100kΩ=16.1kΩ​

When MODE_SEL pin is set to LOW (BD mode), the under-voltage threshold is 7.5 V typical.

does it mean it works with 12v when operating in BD MODE ?

Hi,

I'll take a look at your numbers and get back with further comments by tomorrow.

Best regards,
-Ivan Salazar
Applications Engineer

Hi,

Your math for the PLIMIT seems correct.

I'm not clear on your question about BD MODE and 12V.
If you're setting the device for BD MODE, you'll have to supply PVCC with at least 7.5V so that UVP is not triggered, and if in addition to that you set the PLIMIT as described above, even though you're supplying with >7.5V, the output of the amplifier should not exceed that set by PLIMIT.

Best regards,
-Ivan Salazar
Applications Engineer

thanks for the response ,

this PLIMIT specified is per channel or total PLIMIT for both channels combined  

Hi,

This controls the "virtual voltage rail limit" for both channels simultaneously.

Best regards,
-Ivan Salazar
Applications Engineer

thanks for the response 

i am using 12v supply 

can i  drive  2 watt speaker in 4 ohm config by adjusting the power limit ? 

do we need this caps or when used in single ended line out can i connect to Gnd directly ? When i connect it this way ? 

Also the targeted application is for making announcements or popup sounds 

Hi,

Using 12V supply you have plenty of power to get 2W on 4Ohm. Setting the PLIMIT feature around 2W will create clipping at the output when trying to push more than 2W, as described in section 7.3.3.

You need the input AC coupling caps, this is also mentioned in section 8.2.2.7.

Best regards,
-Ivan Salazar
Applications Engineer