Strictly necessary cookies are on by default and cannot be turned off. Functional, Performance and Tracking/targeting/sharing cookies can be turned on below based on your preferences (this banner will remain available for you to accept cookies). You may change your cookie settings by deleting cookies from your browser. Then this banner will appear again. You can learn more details about cookies HERE.
Strictly necessary (always on)
Functional, Performance and Tracking/targeting/sharing (default off)
Has anyone looked at routing out the 32.768KHz crystal with the 732S (SIP) module. It looks like it has to come all the way around the module to get to the crystal. Seems like a really noisy route. Any suggestions?
JT is tied up this afternoon, so I thought I'd share the answers he received back regarding your question about Xtal placement.
First off, the BCM20732S was designed for both LPO pins as normal GPIO signals.
If an external LPO is required, here's the two proposals we received back from the internal team:
"Place LPO crystal and route traces under BCM20732S, as we know, it is difficult to have enough space to protect other signals from LPO signals when we are bringing out signals from SiP. But this arrangement should be completed by double side placement & SMT."
"Bring out traces with option B of application note and place LPO crystal closed to the LPO pins of BCM20732, and Enlarge the spaces between LPO traces and other signaling traces as possible. Enhanced ground plane (marked in Green in below pic), must not be the same level as External LPO Crystal, in order to protect ground plane. It is recommended that two layers PCB design is minimum, one layer for Ground Plane, another layer for Crystal routing."