DS1742-70 Maxim Integrated Products, DS1742-70 Datasheet - Page 6

• Manufacturer Part Number: DS1742-70
• Description: IC RTC RAM Y2K 5V 70NS 24-EDIP
• Manufacturer: Maxim Integrated Products
• Type: Clock/Calendar/NVSRAM/Y2Kr

Specifications of DS1742-70

• Memory Size: 16K (2K x 8)
• Time Format: HH:MM:SS (24 hr)
• Date Format: YY-MM-DD-dd
• Interface: Parallel
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Through Hole
• Package / Case: 24-DIP (600 mil) Module
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

DS1742
BATTERY LONGEVITY
The DS1742 has a lithium power source that is designed to provide energy for clock activity, and clock
and RAM data retention when the V
supply is not present. The capability of this internal power supply
CC
is sufficient to power the DS1742 continuously for the life of the equipment in which it is installed. For
specification purposes, the life expectancy is 10 years at 25°C with the internal clock oscillator running in
the absence of V
power. Each DS1742 is shipped from Dallas Semiconductor with its lithium energy
CC
source disconnected, guaranteeing full energy capacity. When V
is first applied at a level greater than
CC
V
, the lithium energy source is enabled for battery backup operation. Actual life expectancy of the
PF
DS1742 will be much longer than 10 years since no lithium battery energy is consumed when V
is
CC
present.
BATTERY MONITOR
The DS1742 constantly monitors the battery voltage of the internal battery. The Battery Flag bit (bit 7) of
the day register is used to indicate the voltage level range of the battery. This bit is not writable and
should always be a 1 when read. If a 0 is ever present, an exhausted lithium energy source is indicated
and both the contents of the RTC and RAM are questionable.
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