BQ3285LDSS [Texas Instruments]

The bq3285ED/LD is a fully compatible real-time clock for IBM AT-compatible computers and other applications. The only external components are a 32.768kHz crystal and a backup battery. It provides a time-of-day clock and 100-year calendar with alarm features and battery operation. The architecture is based on the bq3285/7 RTC with added features: low-voltage operation, 32.768kHz output, 128 additional bytes of CMOS, and a day-of-month alarm to be compliant with the ACPI RTC specification. The bq3285ED is intended for use in 5V systems. The bq3285LD is intended for use in 3V systems; however, it may also operate at 5V and then go into a 3V power-down state. It provides system wake-up capability via an alarm interrupt, which is active in battery-backup mode. In battery-backup mode, current drain is less than 550nA. It has selectable Intel or Motorola bus timing and comes in a 24-pin plastic SSOP package.