DS1305 Datasheet, PDF (10/22 Pages) Dallas Semiconductor – Serial Alarm Real Time Clock RTC

Figure 4. POWER-SUPPLY CONFIGURATIONS
DS1305
CONFIGURATION 1: BACKUP SUPPLY IS
NONRECHARGEABLE LITHIUM BATTERY
NOTE: DEVICE IS WRITE-PROTECTED IF VCC < VCCTP.
CONFIGURATION 2: BACKUP SUPPLY IS A
RECHARGEABLE BATTERY OR SUPER
CAPACITOR
NOTE: DEVICE DOES NOT PROVIDE AUTOMATIC WRITE PROTECTION.
CONFIGURATION 3: BATTERY OPERATE
MODE
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