PCM2912A: VDD to Power Oscillator

first_name Grant

Prodigy 70 points

Part Number: PCM2912A

Due to shock requirements we cannot use a crystal.

Can the VDD output be used to power a 4.5mA MEMS oscillator?

If the MIC (VIN) is unused should the pin be left floating or tied to some level?

8 months ago

0 Jeff McPherson 8 months ago

TI__Mastermind 30195 points

Hi,

VDD is an input pin for the digital power supply, not an output.

VIN should be tied to GND with a 0.47uF cap if not being used to prevent noise from coupling into the circuit.

Best regards,
Jeff McPherson

0 first_name Grant 8 months ago in reply to Jeff McPherson

Prodigy 70 points

HI,

The data sheet indicates that VDD is an "Internally-generated power supply voltage".

Was hoping to avoid adding an LDO for the oscillator.

0 Jeff McPherson 8 months ago in reply to first_name Grant

TI__Mastermind 30195 points

Hi,

Sorry, you're right those are all internal supplies generated by Vbus. However I wouldn't use those to supply other devices as they were not designed to be loaded like that. If you want to take advantage of an existing supply, you could probably use VBUS.

Best regards,
Jeff McPherson

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PCM2912A: VDD to Power Oscillator