Is XTAL 32.768KHz a mandatory discrete for CYW920719 ?

[SeunghanLim]

Our customer is testing with CYW920719 as a  module.

They tested with CYW920719B2Q40EVB-01. It works very well to test HCI command.

They made  their own PCB module  by following  EVB(CYW920719B2Q40EVB-01)  all datasheet except 32.768Khz crystal.

But CYW920719  module didn't response for the HCI command.

Because there is not enough space and GPIO pin(15) can be saved, They might drop the 32Khz XTAL.

As I know, XTAL 32K is for the Low power mode.

 1. XTAL 32Khz is mandatory discrete to operate normally?

 2. Can we make a module to operate normally without 32Khz XTAL.

 3. What is the XTAL 32KHz own purpose except Low power mode?

Thank you for your co-operation

BRs

[DheerajPK_41 · Accepted solution]

Hi,

The internal LPO will not be accurate. So there might be some issues whereever the timing is a consideration in the operations carried out, e.g. connection/re-connection. It is mandatorily  used for Low power mode. So it is recommended to use external crystal oscillator. 

Thanks,

-Dheeraj.P.K