PCM5242 44.1KHz EQ ISSUE

Bing Dong

Prodigy 450 points

Other Parts Discussed in Thread: PCM5242

Hi team,

I have a issue about PCM5242 EQ:

Issue: Using 44.1Khz sampling rate ,EQ may not take effect,but 48Khz sampling rate ,it works well.

Testing condition: Using our PCM5242 EVM, PSIA input LRCLK=44.1KHz/48kHz,Bit clock=2.8224MHz,MCLK=11.289MHz,

Configuration in PPC 2 is using Hybridflow1 or 6, There is a EQ at 1Khz -6dB Gain, Q=1.6, xml file is attached for your reference.

Input digital signal is 0.5FFS, 1Khz

Testing results are listed as below, EQ may note take effect at 44.1Khz sampling rate.MyPCM5242MHF6_HF6_44Khz.xml

	GUI Configure in PPC2	LRCLK input	Output voltage
0dB at 1Khz (no EQ)	44.1K	44.1K	4Vrms
-6dB at 1Khz	44.1K	44.1K	4Vrms
-6dB at 1Khz	44.1K	48k	4Vrms
-6dB at 1Khz	48k	48k	1.992Vrms

over 7 years ago

0 Diego Melendez over 7 years ago

TI__Guru 57800 points

Hi, Bing,

Thanks for your question, my colleague will take a look to this and will get back to you soon.

Regards,

-Diego Meléndez López
Audio Applications Engineer

0 Justin Bohr over 7 years ago in reply to Diego Melendez

TI__Mastermind 27850 points

Hi Bing,

Are you changing the sampling rate physically with the clock as well as in the GUI drop down? It will require a reprogramming of the DSP as well to change the coefficients. This means that in the GUI you will have to stop the DSP by hitting the red button in the top right, then change the sampling rate, then start the DSP again. If you want to test if you have the biquad enabled, but for the wrong sampling rate, do a frequency response and see if your desired response is just shifted in frequency.

Justin

Audio

Audio forum

PCM5242 44.1KHz EQ ISSUE