BQ3287EAMT

Product Summary

The BQ3287EAMT is a low-power microprocessor peripheral providing a time-of-day clock and 100-year calendar with alarm features and battery operation. Other features include three maskable interrupt sources, squarewave output, and 242 bytes of general nonvolatile storage. A 32.768kHz output is available for sustaining power-management activities. Wake-up capability is provided by an alarm interrupt, which is active in battery-backup mode. The BQ3287EAMT is a fully compatible real-time clock for IBM AT-compatible computers and other applications. The BQ3287EAMT write-protects the clock, calendar, and storage registers during power failure. The integral backup energy source then maintains data and operates the clock and calendar.

Parametrics

BQ3287EAMT absolute maximum ratings: (1)DC voltage applied on VCC relative to VSS, VCC: -0.3 to 7.0 V; (2)DC voltage applied on any pin excluding VCC relative to VSS, VT≤VCC + 0.3, VT: -0.3 to 7.0 V ; (3)Operating temperature, TOPR: 0 to +70℃ ; (4)Storage temperature, TSTG: -40 to +70℃; (5)Temperature under bias, TBIAS: -10 to +70℃; (6)Soldering temperature, for 10 seconds, TSOLDER: 260℃.

Features

BQ3287EAMT features: (1)Direct clock/calendar replacement for IBM-compatible computers and other applications; (2)Functionally compatible with the DS1287/DS1287A and MC146818A/ MC146818B; (3)242 bytes of general nonvolatile storage; (4)Provides a 32.768kHz output for power management; (5)System wake-up capability-alarm interrupt active in battery-backup mode; (6)Integral lithium cell and crystal; (7)160 ns cycle time allows fast bus operation; (8)14 bytes for clock/calendar and control; (9)Time of day in seconds, minutes, and hours, 12- or 24-hour format; Optional daylight saving adjustment; (10)Calendar in day of the week, day of the month, months, and years; (11)with automatic leap-year adjustment; (12)Programmable square wave output; (13)Three individually maskable interrupt event flags: Periodic rates from 122ms to 500ms; Time-of-day alarm once per second to once per day; End-of-clock update cycle; (14)Better than one minute per month clock accuracy.

Diagrams