COM Express® PMC/XMC Lite Carrier
Users Guide
Document:
CTIM-00440
Revision:
0.04
Page 24 of 29
Connect Tech Inc. 800-426-8979 | 519-836-1291
Date:
2017-09-11
RTC Battery
This carrier has a Panasonic BR1225A/FA Lithium battery providing 3V@ 48mAh to VBAT. VBAT is the
supply for the RTC Clock of the COM Express module.
If the BR1225A is not sufficient for the application, an external battery can be connected to P17 with J2
selection jumper set appropriately.
For further information about RTC battery selection and life time estimation, see Application Note 00009
CTIN-00009 http://connecttech.com/pdf/CTIN-00009.pdf
Note: the battery ships with a non-conductive label to prevent accidental discharge. It can be removed before
installation.
J2 Jumper – RTC Battery
Function
RTC Battery Selection
Location
J2
Modes
Position
Description
EXT
External RTC Battery
LOC
On-Board RTC Battery
J3 Jumper – RTC Battery
Function
RTC Battery Clear/Enable
Location
J3
Modes
Position
Description
CLR
Clear RTC
EN
Enable RTC