101-0440 Rabbit Semiconductor, 101-0440 Datasheet - Page 167

• Manufacturer Part Number: 101-0440
• Description: CARD 8-RELAYS SR9510 SMARTSTAR
• Manufacturer: Rabbit Semiconductor

Specifications of 101-0440

• Accessory Type: Smart Star Relay Card
• For Use With/related Products: SR9150
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

C.2.1 Replacing the Backup Battery
The battery is user-replaceable, and is fitted in a battery holder. To replace the battery, lift
up on the spring clip and slide out the old battery. Use only a Panasonic CR2330 or equiv-
alent replacement battery, and insert it into the battery holder with the + side facing up.
C.2.2 Battery-Backup Circuit
Figure C-1 shows the battery-backup circuit.
The battery-backup circuit serves three purposes:
• It reduces the battery voltage to the SRAM and to the real-time clock, thereby limiting
• It ensures that current can flow only out of the battery to prevent charging the battery.
• A voltage, VOSC, is supplied to U14, which keeps the 32.768 kHz oscillator working
VRAM and Vcc are nearly equal (<100 mV, typically 10 mV) when power is supplied to
the CPU Card.
User’s Manual
the current consumed by the real-time clock and lengthening the battery life.
when the voltage begins to drop.
NOTE: The SRAM contents and the real-time clock settings will be lost if the battery is
CAUTION: There is an explosion danger if the battery is short-circuited, recharged, or
replaced with no power applied to the Smart Star. There is a provision for an external bat-
tery if you need to save the SRAM contents and the real-time clock settings since the CPU
Card needs to be removed from the backplane in order to change the onboard battery.
replaced incorrectly. Replace the battery only with the same type or an equivalent type
recommended by the battery manufacturer. Dispose of used batteries according to the
battery manufacturer’s instructions.
Figure C-1. Smart Star CPU Card Backup Battery Circuit
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