PCM1863: Does the PCM1863 require input buffer?

Nigel Taylor

Part Number: PCM1863

Support Path: /Product/Help with Device Selection/Audio solutions/

I'm using the PCM1863 in an Audio design (multiple channels) I wanted to understand if I can rely on the internal analogue circuitry i.e. integrated buffer rather than external input buffer. Are there any reference designs other than the EVM kit available to share or is this the suggested input. The inputs are are likely to be both single ended and differential hence this is why I selected this device as it as a universal input i.e can take either diff and or SE (5Vpk-pk)

Currently I'm using the EVM approach 100K to GND and 10uF in series with the input, I also have a Analogue switch at the input before these components to allow Isolation from external audio devices up on initial connection, also not sure whether to add clamping diodes.

Thanks

Nigel

over 8 years ago

0 Diego Melendez over 8 years ago

TI__Guru 57800 points

HI, Nigel,

As you mention, the PCM1863 features an universal front-end capable of accepting either single ended or differential signals, having the option to mix them internally as required by the end user. The EVM of the device showcases the suggested implementation of the device, we usually recommend to follow the design of the EVM as close as possible.

Best Regards,

-Diego Meléndez López
Audio Applications Engineer

0 Nigel Taylor over 8 years ago in reply to Diego Melendez

Intellectual 345 points

Hi Diego, thanks for the prompt response much appreciated, do you have any tech notes on clocking schemes for Multiple PCM18x devices ?

Thanks
Nigel

0 Diego Melendez over 8 years ago in reply to Nigel Taylor

TI__Guru 57800 points

Hi, Nigel,

The PCM186x family of audio ADCs have an option to be configured in TDM mode. In this mode, PCM186x devices require a fixed 256×Fs BCLK, allowing up to eight channels of 32-bit data in a single audio serial bus. Please refer to below diagram as reference:

For more general information about TDM transmission mode, please refer to the following app notes. These documents are specified for other devices, but the TDM concept is similar for the PCM186x family.

Using TDM Function to Interface Four TLV320AIC33 Codecs With a Single Host Processor

Using TLV320AIC3x Digital Audio Data Serial Interface With Time-Division Multiplexing Support

Best Regards,

-Diego Meléndez López
Audio Applications Engineer

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PCM1863: Does the PCM1863 require input buffer?