STA309A - 2.1 Configuration - L/R PWM + Line-Out Woofer

[aaron239955_stm1_stmicro_com]

Posted on September 28, 2015 at 20:32

I am trying to use one I2S input and send out L/R stereo as standard class-D PWMs and output the subwoofer at line level. My confusion arises with properly setting up the cross-over and how to use the DDX Headphone output to create a line level signal. What configuration would you recommend to achieve this? Is there a way to switch between two different I2S inputs like a A/B selector in this configuration?

#audio-processing #sta309a

[jorge]

Posted on October 06, 2015 at 05:57

I'm also very interested in this topic. I wish to connect the headphone output of a STA311B, which I'm assuming would be very similar to the STA309A circuit. 

In both datasheets the connection is mentioned, but in none a sample schematic is provided.

Can you share a sample schematic? 

[Nickname1623_O]

Posted on October 19, 2015 at 11:38

hi Loebold ,

for STA309A or STA311B , there are 8 processing channels in side , and you are able to map any input to any processing channel or mix them together .

then for your applicaiton , you can use channel 1 and 2 as  I2S input channel , and map them to 3 and 4 channel .

after that , you can apply PWM output from channel 1 and 2 for stereo class D output , and mixed channel 3 and 4 output togethr ( -6dB each channel  ) , also added 1 or 2 low pass filter in channel3 or 4 output , finally you can get woofer output from channel 3 or 4 .

since individual channel control are available , so you just need to use channel mute to control output level of them .

thanks ,

YT