Product Summary

The DS12887 Real Time Clock plus RAM is designed to be a direct replacement for the DS1287. The DS12887 is identical in form, fit, and function to the DS1287, and has an 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. A lithium energy source, quartz crystal, and write–protection circuitry are contained within a 24–pin dual in-line package. As such, the DS12887 is a complete subsystem replacing 16 components in a typical application.

Parametrics

DS12887 absolute maximum ratings: (1)Voltage on Any Pin Relative to Ground:–0.3V to +7.0V; (2)Operating Temperature: 0℃ to 70℃; (3)Storage Temperature: –40℃to +70℃; (4)Soldering Temperature: 260℃ for 10 seconds (See Note 7).

Features

DS12887 features: (1)Drop–in replacement for IBM AT computer clock/calendar; (2)Totally nonvolatile with over 10 years of operation in the absence of power; (3)Self–contained subsystem includes lithium, quartz, and support circuitry; (4)Counts seconds, minutes, hours, days, day of the week, date, month, and year with leap; (5)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 Savings Time option; (9)Selectable between Motorola and Intel bus timing; (10)Multiplex bus for pin efficiency.

Diagrams

DS12887 BLOCK DIAGRAM 

Image Part No Mfg Description Data Sheet Download Pricing
(USD)		 Quantity
DS12887+
DS12887+
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
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
DS12887
DS12887
Maxim Integrated Products
Real Time Clock
Data Sheet
Negotiable