TLV320ADC5120: how to use the DRC to limit the I2S output level

Anderson Cheng

Part Number: TLV320ADC5120

Hi team,

how to use the DRC to limit the I2S output level,

I didn't see any change when use AP doing step level sweep, modifying the DRC 'signal level threshold' and 'max gain allowed'.

can you explain what is the meaning of this two setup ?

customer target application:

single end input: 1Vrms input limit to -6dBFS output. >1Vrms input also limit to -6dBFS output.

Thanks.

Anderson

over 1 year ago

0 Daveon Douglas over 1 year ago

TI__Mastermind 27270 points

Hi Anderson,

Can you clarify on the customer's goal again?

The DRC will apply a gain to low level signals below the defined threshold. You can verify this by disabling the DRC, applying a low level signal, checking the output, then enabling the DRC to see the difference on the output.

0 Anderson Cheng over 1 year ago in reply to Daveon Douglas

TI__Intellectual 1260 points

Hi Daveon,

What customer want to achieve is like below effect: please let me know how to set the DRC or AGC parameter to achieve this goal.

also does the attack time and release time of DRC is adjustable?

0 Daveon Douglas over 1 year ago in reply to Anderson Cheng

TI__Mastermind 27270 points

Hi Anderson,

Since you want to keep the output at a constant -6dbFS I suggest using the AGC instead of the DRC. You can set the target threshold and max gain allowed to be added to the signal in PPC3. You can direct write via i2c to change the attack/release time explained in this app note:

Using the Automatic Gain Controller in TLV320ADCx120 and PCMx120-Q1 Family (Rev. A)

Regards,

Audio

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TLV320ADC5120: how to use the DRC to limit the I2S output level