PCM1808: PCM1808 Zero Data

allan chiang

Part Number: PCM1808

Regarding I2S Dout Pin for pcm1808, may I have a way to make the Dout Pin output to be zero under the analog signal without input status?

over 8 years ago

0 Diego Melendez over 8 years ago

TI__Guru 57800 points

Hi, Allan,

The digital output of the PCM1808 will stream the analog input content, the Zero data is sent when the input is set to the common mode voltage, this can be accomplished by connecting the input to GND through a decoupling cap. This part doesn't have an automatic mute that could be configured to send zero data when no input is detected.

If you want to send zero data when the input signal is removed (as disconnecting the audio cable from connector), there are a couple connectors with an option to ground the input when no cable is attached.

Regards,

-Diego Meléndez López
Audio Applications Engineer

0 allan chiang over 8 years ago in reply to Diego Melendez

Intellectual 620 points

I just test PCM1808 signal directly to the pin 13 and 14 directly grounded, measurement I2S_data out on pin 9 or output waveform is not Low output !!

0 Diego Melendez over 8 years ago in reply to allan chiang

TI__Guru 57800 points

Hi, Allan,

Thanks for the feedback. You are right, the data is not zero as the ADC will still send the LSBs of data through the DOUT pin. Can you please provide more details about your requirement of having a low output from DOUT?.

Best Regards,

-Diego Meléndez López
Audio Applications Engineer

0 allan chiang over 8 years ago in reply to Diego Melendez

Intellectual 620 points

I hope there is a way to make Dout output 0

0 Diego Melendez over 8 years ago in reply to allan chiang

TI__Guru 57800 points

Allan,

The PCM1808 does not have a user-configurable mute option to send Zero data on DOUT. The part will mute itself and will send ZERO data when loss of synchronization on the I²S clocks is detected. Please refer to Figure 23 of the datasheet. Another way to force the device to send ZERO data is to set SCKI clock fixed to low or high, as indicated on Figure 3.

Best Regards,

-Diego Meléndez López
Audio Applications Engineer

0 allan chiang over 8 years ago in reply to Diego Melendez

Intellectual 620 points

I know you start ZERO data conditions, I was wondering if there is any way to achieve ZERO data effect

0 Diego Melendez over 8 years ago in reply to allan chiang

TI__Guru 57800 points

Hi, Allan,

This is a simple device with limited configuration options so unfortunately there is no way to configure the device to send zero data output.

Best Regards,

-Diego Meléndez López
Audio Applications Engineer

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PCM1808: PCM1808 Zero Data