PCM2903C: PCM2903C

Nik Krevelj

Part Number: PCM2903C

Tool/software:

Hello,

I am trying to use the PCM2903C for Digitizing 2 pre-amplified electret microphone signals and transferring the data via USB to a PC.

My question is, what is the recommendation for wiring the many pins that are unused in my setup, for example the HID, SEL and VOUT pins etc. Should they go directly to GND/VCC or through capacitors? I found some info in the datasheet but not everything.

I have provided a KiCad screenshot of the current schematic and would appreciate some feedback.

Regards,

Nik Krevelj

10 months ago

0 Jeff McPherson 10 months ago

TI__Mastermind 48205 points

Hi Nik,

HID can be tied to GND directly since they are logic input signals (active high)

SEL must be used. As you have it already, SEL0 must be high. But SEL1 must be VBUS which is typically 5V, not 3.3V

VOUT can remain floating.

Best regards,
Jeff McPherson

0 Nik Krevelj 10 months ago in reply to Jeff McPherson

Prodigy 30 points

Thank you for the informative reply!

I have one more quick question. Does isolating the analog and digital grounds provide any improvements? The eval board and the datasheet have the grounds connected so I assume there is no real performance benefits.

0 Jeff McPherson 10 months ago in reply to Nik Krevelj

TI__Mastermind 48205 points

Hi Nik,

No it is not a critical concern for this device. Just good PCB practices are needed i.e. don't run analog signals over/under digital signals, keep decoupling close to the device, etc.

Best regards,
Jeff McPherson

Audio

Audio forum

PCM2903C: PCM2903C