Product Summary

The DS12887A real time clock plus RAM is designed to be a direct replacement for the DS1287A. The DS12887A is identical in form, fit, and function to the DS1287A, and includes additional 64 bytes of general-purpose RAM. Access to this additional RAM space is determined by the logic level presented on AD6 during the address portion of an access cycle.

Parametrics

DS12887A absolute maximum ratings: (1)Voltage Range on VCC Pin Relative to Ground: -0.3V to +6.0V; (2)Operating Temperature Range, Commercial (noncondensing): 0℃ to +70℃; (3)Operating Temperature Range, Industrial (noncondensing): -40℃ to +85℃; (4)Storage Temperature Range, EDIP: -40℃ to +85℃; PDIP, SO, PLCC, TQFP: -55℃ to +125℃; (5)Lead Temperature (soldering, 10s): +260℃; (6)Soldering Temperature (reflow), PDIP, SO, PLCC: +260℃; TQFP: +245℃.

Features

DS12887A features: (1)Drop-in replacement for IBM AT computer clock/calendar; (2)Pin compatible with the MC146818B and DS1287A; (3)Totally nonvolatile with over 10 years of operation in the absence of power; (4)Self-contained subsystem includes lithium, quartz, and support circuitry; (5)Counts seconds, minutes, hours, days, day of the week, date, month, and year with leapyear compensation valid up to 2100; (6)Binary or BCD representation of time, calendar, and alarm; (7)12-hour or 24-hour clock with AM and PM in 12-hour mode; (8)Daylight Savings Time option; (9)Selectable between Motorola and Intel bus timing; (10)Multiplex bus for pin efficiency; (11)Interfaced with software as 128 RAM locations: 14 bytes of clock and control registers; 114 bytes of general-purpose RAM; (12)Programmable square-wave output signal; (13)Bus compatible interrupt signals (IRQ); (14)Three interrupts are separately software maskable and testable, Time-of-day alarm once/second to once/day; (15)Underwriters Laboratory (UL) recognized.

Diagrams

DS12887A block diagram

Image Part No Mfg Description Data Sheet Download Pricing
(USD)
Quantity
DS12887A
DS12887A

Maxim Integrated Products

Real Time Clock

Data Sheet

Negotiable 
DS12887A+
DS12887A+

Maxim Integrated Products

Real Time Clock RTC

Data Sheet

0-1: $6.62
1-25: $4.45
25-50: $3.23
50-100: $3.19