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GENERAL DESCRIPTION
The DS1216 SmartWatch RAM and SmartWatch
ROM sockets are 600-mil-wide DIP sockets with a
built-in CMOS watch function, an NV RAM
controller circuit, and an embedded lithium energy
source. The sockets provide an NV RAM solution
for memory sized from 2K x 8 to 512K x 8 with
package sizes from 26 pins to 32 pins. When a
socket is mated with a CMOS SRAM, it provides a
complete solution to problems associated with
memory volatility and uses a common energy
source to maintain time and date. The SmartWatch
ROM sockets use the embedded lithium source to
maintain the time and date only. A key feature of
the SmartWatch is that the watch function remains
transparent to the RAM. The SmartWatch monitors
VCC for an out-of-tolerance condition. When such a
condition occurs, an internal lithium energy source
is automatically switched on and write protection
is unconditionally enabled to prevent loss of watch
and RAM data.
TYPICAL OPERATING CIRCUIT
FEATURES
Keeps Track of Hundredths of Seconds,
Seconds, Minutes, Hours, Days, Date of the
Month, Months, and Years
Converts Standard 2K x 8 Up to 512K x 8
CMOS Static RAMs into Nonvolatile Memory
Embedded Lithium Energy Cell Maintains
Watch Information and Retains RAM Data
Watch Function is Transparent to RAM
Operation
Automatic Leap Year Compensation Valid Up
to 2100
Lithium Energy Source is Electrically
Disconnected to Retain Freshness Until Power
is Applied for the First Time
Proven Gas-Tight Socket Contacts
Full ±10% Operating Range
Accuracy Better Than ±1 Minute/Month
at +25°C
ORDERING INFORMATION
PART
TEMP RANGE PIN-PACKAGE
DS1216B
0°C to +70°C
28 SmartWatch Socket
DS1216C
0°C to +70°C
28 SmartWatch Socket
DS1216D
0°C to +70°C
32 SmartWatch Socket
DS1216E
0°C to +70°C
28 SmartWatch Socket
DS1216F
0°C to +70°C
32 SmartWatch Socket
DS1216H
0°C to +70°C
32 SmartWatch Socket
(See Figure 2 for letter suffix marking identification.)
Selector Guide appears on page 2.
DS1216
SmartWatch RAM (DS1216B/C/D/H);
SmartWatch ROM (DS1216E/F)
19-6075; Rev 11/11