Figure 4.12 Battery Backup - Samsung OfficeServ 12 Service Manual

4.2.2.12 Battery Backup
The battery switch controls the power supplied when power of SRAM and RTC fails.
Setting the backup switch to 'Off' will delete all data and settings of SRAM and RTC.
Thus, in order to erase all backup data in SRAM(Static Random Access Memory), leave
the switch on 'Off' status for approximately 10 seconds and turn the switch on again.
The switch is set to 'Off' during production for system safety.
5.0 V
3.3 V
Schottky diodes having 0.2 V Forward Voltage Drop are used, and a 1.0 F super capacitor
is used for VBAT(Voltage of Battery).
SRAM runs on approximately 3.1 V when operating on system power, and uses 2.9 V
backup battery power for storing data when the system power is off.
RTC runs on approximately 4.8 V when operating on system power, and uses 2.9 V backup
battery power for storing data when the system power is off.
In any case, the minimum retention voltage required by devices is satisfied.
4.2.2.13 Trunk/MGI board Connection Connector
The base board of OfficeServ 12 has a 50pin connector for mounting a trunk daughter
board(3/4TRK, 2BRI), and two 40pin connectors for mounting a VoIP daughter
board(MGI).
© SAMSUNG Electronics Co., Ltd.
VBAT

Figure 4.12 Battery Backup

4.8 V or 2.9 V
RTC
SRAM
3/1 V or 2.9 V
18