DS14287

Product Summary

The DS14287 is a Real Time Clock with NVRAM Control. It provides the industry standard DS1287 clock function with the additional feature of providing nonvolatile control for an external SRAM. Functions include a nonvolatile time-of-day clock, alarm, 100-year calendar, programmable interrupt, square wave generator, and 114 bytes of nonvolatile static RAM. The DS14287 uses its backup energy source and battery-backup controller to make a standard CMOS static RAM nonvolatile during power-fail conditions. For the DS14287 the internal lithium cell is electrically isolated from the clock and memory when shipped from the factory.

Parametrics

DS14287 absolute maximum ratings: (1)Voltage Range on Any Pin Relative to Ground:-0.5V to +7.0V ; (2)Storage Temperature Range:-40℃ to +85℃; (3)Soldering Temperature: DIP:260℃ for 10 seconds; (4)Soldering Temperature: Surface Mount:See IPC/JEDEC Standard J-STD-020.

Features

DS14287 features: (1)Direct Replacement for IBM AT Computer Clock/Calendar ; (2)Functionally Compatible with the DS1285/DS1287 ; (3)Available as Chip or Stand-Alone Module with Embedded Lithium Battery and Crystal ; (4)Automatic Backup Supply and Write Protection to Make External SRAM Nonvolatile ; (5)Counts Seconds, Minutes, Hours, Days, Day of the Week, Date, Month, and Year with Leap Year Compensation Valid Up to 2100 ; (6)Binary or BCD Representation of Time, Calendar, and Alarm ; (7)12- or 24-Hour Clock with AM and PM in 12-Hour Mode ; (8)Daylight Saving Time Option ; (9)Multiplex Bus for Pin Efficiency ; (10)Interfaced with Software as 128 RAM Locations ; (11)14 Bytes of Clock and Control Registers ; (12)114 Bytes of General Purpose RAM ; (13)Programmable Square-Wave Output Signal ; (14)Bus-Compatible Interrupt Signals (IRQ) ; (15)Three Interrupts are Separately Software-Maskable and Testable Time-of-Day Alarm Once/Second to Once/Day ; (16)Periodic Rates from 122μs to 500ms ; (17)End of Clock Update Cycle ; (18)Optional Industrial Temperature Version Available: DS14285 DIP, SO, and PLCC.

Diagrams