Description

Benchmarq BQ3287AMT - Real-Time Clock (RTC) Module Simple Type: Accessory The CMOS bq3287/bq3287A is a low-power microprocessor periph eral providing a time-of-day clock and 100-year calendar with alarm features and battery operation. Other features include three maskable interrupt sources, square wave output, and 114 bytes of gen eral nonvolatile storage. The bq3287A version is identical to the bq3287, with the addition of the RAM clear input. The bq3287 is a fully compatible real-time clock for IBM AT compatible computers and other applications. The bq3287 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. As shipped from Benchmarq, the real time clock is turned off to maximize battery capacity for in-system operation. The bq3287 is functionally equivalent to the bq3285, except that the battery (16, 20) and crystal (2, 3) pins are not accessible. These pins are connected internally to a coin cell and quartz crystal. The coin cell is sized to provide 10 years of data retention and clock operation in the absence of power. For a complete description of features, operating conditions, electrical characteristics, bus timing, and pin descriptions. Download the datasheet (PDF)