BQ3285LDSSTRG4

The Texas Instruments BQ3285LDSSTRG4 is a low-power microprocessor peripheral that provides a time-of-day clock and a 100-year calendar with alarm features and battery operation. It is functionally compatible with the DS1285 and closely matches the MC146818A pin configuration.

This RTC IC supports a voltage range of 2.4V to 4V and operates at 0°C to 70°C. It features a parallel interface, 242 bytes of general nonvolatile storage, and a 32.768kHz output for power management. The device includes system wake-up capability via an alarm interrupt active in battery-backup mode, and consumes less than 0.5µA under battery operation.

Key features include selectable Intel or Motorola bus timing, 14 bytes for clock/calendar and control, and BCD or binary format for clock and calendar data. The calendar supports automatic leap-year adjustment, and the time of day can be displayed in 12- or 24-hour format with optional daylight saving adjustment. It also offers a programmable square wave output and three individually maskable interrupt event flags.

The BQ3285LDSSTRG4 is supplied in a 24-SSOP package for surface mounting. It is designed as a direct clock/calendar replacement for IBM AT-compatible computers and other applications. The only external components required are a 32.768kHz crystal and a backup battery.