PCM1803a help with no D out

Pat Gibson

Other Parts Discussed in Thread: PCM1803A, PCM1808

Hi everyone

I Cant seem to get this device to work, I have gone over the data sheet several times and don't seem to be getting anywhere

I have used one of the PCM1803a breakout boards that are available, mainly to see how it will work before I go as far as making up PCBs.

I have set FMT0 and FMT1 to 5v and the same with MOD0 and Mod1, this should have set the device as master with a right justified 20 bit data

the breakout board has a 2.56mhz oscillator feeding SCK (pin 15).

As the device is set in master I assumed that once powered up with an analog input on VINL and VINR I would have at least clock signals from BCK or LRCK but I have absolutely nothing.

I have 2 of these boards and it is the exact same with both,

over 10 years ago

0 Justin Bohr over 10 years ago

TI__Mastermind 27990 points

Hi Pat,

In the data sheet it specifies that the minimum system clock is 8.192 MHz. A 2.56 MHz oscillator will not be enough to drive this part. When you mention a breakout board are you referring to the Tiny Tool Kit? This has a PCM1808 that uses a 12.288 MHz crystal.

Justin

0 Pat Gibson over 10 years ago in reply to Justin Bohr

Prodigy 40 points

Hi sorry my mistake, it's a 24.576mhz. I should have read what I'd typed properly, My wireless keyboard drivese

Mad at times

The breakout board is one of the sparkfun variety, which can be found here.

0 Justin Bohr over 10 years ago in reply to Pat Gibson

TI__Mastermind 27990 points

Hi Pat,

What signal is being applied to the PDWN pin?

Justin

0 Pat Gibson over 10 years ago in reply to Justin Bohr

Prodigy 40 points

Thank you :)
How did I miss that ???

Although I'm not in the workshop at the moment to test it, but I bet that's what it is, I have a feeling that I left that floating as I read earlier on in the datasheet that power down was active when LOW, and dont remember setting it high.

0 Pat Gibson over 10 years ago in reply to Pat Gibson

Prodigy 40 points

Thanks everyone, a simple case of a floating PDWN was all it was.

Now need to start on the next part of the project.

Audio

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PCM1803a help with no D out