PCM3008 Sampling Rates

Brian Prorok

Other Parts Discussed in Thread: PCM3008

According to the datasheet, the PCM3008 is capable of sampling rates from 8kHz to 48kHz. I have been unable to use the device at sampling rates less than 16kHz without generating significant noise out of the DAC. Does the standard configuration work for the lower sampling rates or do they require design adjustments?

over 11 years ago

0 Patrick Galvin over 11 years ago

TI__Genius 16270 points

Brian,

What are the clocks coming into the device, and are they set in the appropriate ratios for 8khz sampling? If you have a schematic can you attach that as well?

0 Brian Prorok over 11 years ago in reply to Patrick Galvin

Prodigy 50 points

Patrick,

Our sysck is 2971903.2258Hz, the sampling rate is 11612.90323Hz.

0 Brian Prorok over 11 years ago in reply to Patrick Galvin

Prodigy 50 points

Patrick,

I've attached a wav file of the noise.

0 Brian Prorok over 11 years ago in reply to Patrick Galvin

Prodigy 50 points

Trying a different format for the snapshot.

8182.PCM3008_3.pdf

0 Brian Prorok over 11 years ago in reply to Patrick Galvin

Prodigy 50 points

The PCM3008 does not work at sampling rates less than 16kHz without significant low pass filtering on the DAC output. The onchip output filtering on the DAC is designed to filter the shaped noise for higher sampling rates.

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PCM3008 Sampling Rates