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
` Month and year determine the number of days in each month; 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
` Operating temperature range: 0 to +70
` Accuracy is better than ±1 minute/month @+25Pinout
SpecificationsVoltage Range on any Pin Relative to Ground .........-0.3V to +7.0V for 5V
Operating Temperature Range ........................................0°C to +70°C
Storage Temperature Range........................................ -40°C to +70°C
Soldering Temperature Range ......See J-STD-020A Specification (Note 6)
* This is a stress rating only and functional operation of the device at these or any other conditions beyond those indicated in the operation sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods of time can affect reliability.
DescriptionThe DS1216 SmartWatch RAM and SmartWatch ROM Sockets are 600mil-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 DS1216 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.
Using the DS1216 saves PC board space since the combination of DS1216 and the mated RAM take up no more area than the memory alone. The DS1216 uses the VCC, data I/O 0, CE , OE , and WE for RAM and watch control. All other pins are passed straight through to the socket receptacle.
The DS1216 provides timekeeping information including hundredths of seconds, seconds, minutes,hours, days, date, months, and years. The date at the end of the month is automatically adjusted for months with fewer than 31 days, including correction for leap years. The SmartWatch operates in either 24-hour or 12-hour format with an AM/PM indicator.
DS1216 Data Sheet
