[FAQ] AM623: MCU_OSC0 transconductance parameter

Hello Steve

Thank you for the query.

The parameters and the recommendations related to selection are available in the below section.

7.8.3 High-Frequency Oscillator (HFOSC) Electrical Characteristics

7.11.4 Clock Specifications

Antenna_Head said:

Regarding the MCU_OSC0 Internal Oscillator circuit, could you provide the trans-conductance (gm_critical) of it. We could not find the information in the datasheet. We are in contact with [Crystal Manufacturer] for matching xtal for AM62x.

I am not sure on the availability of this parameter.

Is there a specific use case?

Regards,

Sreenivasa

They are working with the crystal manufacturer to select a the most cost optimized device they can find.  A smaller crystal/package is appealing from both cost and space perspectives, but will require higher gain (gm_critical) from the crystal drive amplifier within the AM62x to startup the oscillator properly.

Hello Steve

Thank you for the inputs.

Please note inputs i received from the expert

We do not define a transconductance value due for the oscillator implemented in AM62x. Customer should select a crystal that meets the ESR, and shunt capacitance requirements defined in the AM62x datasheet.  This will ensue the oscillator starts.  The drive will be reduced internally once the crystal circuit has begun to oscillate.

Regards,

Sreenivasa