Real Time Clock Parallel 16Byte 28-Pin SOIC T/R

The bq4802Y/bq4802LY real-time clock is a low-powermicroprocessor peripheral that integrates a time-ofdayclock, a century-based calendar, and a CPU supervisor,with package options including a 28-pin SOIC,TSSOP, or SNAPHAT that requires the bq48SH-28x6to complete the two-piece module. The bq4802Y/bq4802LY is ideal for fax machines, copiers, industrialcontrol systems, point-of-sale terminals, data loggers,and computers.The bq4802Y/bq4802LY provides direct connectionsfor a 32.768-kHz quartz crystal and a 3-V backupbattery. Through the use of the conditional chip enableoutput (CEOUT) and battery voltage output (VOUT) pins,the bq4802Y/bq4802LY can write-protect and makenon- volatile external SRAMs. The backup cell powersthe real-time clock and maintains SRAM information inthe absence of system voltage. The crystal and batteryare contained within the modules for a more integratedsolutionThe bq4802Y/bq4802LY contains a temperaturecompensatedreference and comparator circuit thatmonitors the status of its voltage supply. When thebq4802Y/bq4802LY detects an out-of-tolerancecondition, it generates an interrupt warning and subsequentlya microprocessor reset. The reset staysactive for 200 ms after VCC rises within tolerance, toallow for power supply and processor stabilization. Thereset function also allows for an external push-buttonoverride

• Real-Time Clock Counts Seconds Through Centuries in BCD Format
• bq4802Y: 5-V Operation
• bq4802LY: 3.3-V Operation
• On-Chip Battery-Backup Switchover Circuit With Nonvolatile Control for External SRAM
• Less Than 500 nA of Clock Operation Current in Backup Mode
• Microprocessor Reset With Push-Button Override
• Independent Watchdog Timer With Programmable Time-Out Period
• Power-Fail Interrupt Warning
• Programmable Clock Alarm Interrupt Active in Battery-Backup Mode
• Programmable Periodic Interrupt
• Battery-Low Warning
• 28-pin SOIC, TSSOP, and SNAPHAT Package Options