RTC IC W NVSRAM Control, Watchdog Timer, UP Reset, Interrupts And Battery Low Warning

The BQ4845 Real-Time Clock is a low-power Microprocessor peripheral that integrates a time-of-day Clock a 100-year calendar, and a CPU Microprocessor Supervisor in a 28-pin SOIC or DIP. The BQ4845 is ideal for fax machines, copiers, Industrial Control systems, point-of-sale terminals, data loggers, and computers.
The BQ4845 provides direct connections for a 32.768KHz quartz crystal and a 3V backup battery. Through the use of the conditional chip enable output (CEOUT) and battery voltage output (VOUT) pins, the BQ4845 CAN write-protect and make nonvolatile external SRAMs The backup cell powers the Real-Time Clock and maintains SRAM information in the absence of system voltage.
The BQ4845 contains a temperature-compensated reference and Comparator circuit that monitors the status of its voltage supply. When the BQ4845 detects an out-of-tolerance condition, it generates an interrupt warning and subsequently a Microprocessor reset. The reset stays active for 200ms after VCC rises within tolerance, to allow for power supply and processor stabilization.
The BQ4845 also has a built-in watchdog Timer to monitor processor operation. If the Microprocessor does not toggle the watchdog input (WDI) within the programmed time-out period, the BQ4845 asserts WDO and RST. WDI unconnected disables the watchdog Timer
The BQ4845 CAN generate other interrupts based on a Clock alarm condition or a periodic setting. The alarm interrupt CAN be set to occur from once per second to once per month. The alarm CAN be made active in the battery-backup mode to serve as a system wake-up call. For interrupts at a rate beyond once per second, the periodic interrupt CAN be programmed with periods of 30.5us to 500ms.
By Texas Instruments
Part Manufacturer Description Datasheet Samples
BQ4845P Texas Instruments 0 TIMER(S), REAL TIME CLOCK, PDIP28, 0.600 INCH, PLASTIC, DIP-28
BQ4845YS-N Texas Instruments 1 TIMER(S), REAL TIME CLOCK, PDSO28
BQ4845S-A4NTR Texas Instruments RTC IC W NVSRAM Control, Watchdog Timer, uP Reset, Interrupts and Battery Low Warning 28-SOIC
BQ4845YS-A4NTR Texas Instruments RTC IC W NVSRAM Control, Watchdog Timer, uP Reset, Interrupts and Battery Low Warning 28-SOIC
BQ4845S-A4NTRG4 Texas Instruments RTC IC W NVSRAM Control, Watchdog Timer, uP Reset, Interrupts and Battery Low Warning 28-SOIC
BQ4845YS-A4TR Texas Instruments RTC IC W NVSRAM Control, Watchdog Timer, uP Reset, Interrupts and Battery Low Warning 28-SOIC 0 to 70
BQ4845YS Texas Instruments 0 TIMER(S), REAL TIME CLOCK, PDSO28, 0.300 INCH, PLASTIC, SOIC-28
BQ4845S-A4TR Texas Instruments RTC IC W NVSRAM Control, Watchdog Timer, uP Reset, Interrupts and Battery Low Warning 28-SOIC 0 to 70
BQ4845YS-A4TRG4 Texas Instruments RTC IC W NVSRAM Control, Watchdog Timer, uP Reset, Interrupts and Battery Low Warning 28-SOIC 0 to 70
BQ4845YS-A4NTRG4 Texas Instruments 1 TIMER(S), REAL TIME CLOCK, PDSO28, 0.300 INCH, GREEN, SOIC-28
BQ4845 's PackagesBQ4845 's pdf datasheet
BQ4845P-A4 PDIP
BQ4845S-A4 SOIC
BQ4845S-A4G4 SOIC
BQ4845S-A4N SOIC
BQ4845S-A4NG4 SOIC
BQ4845S-A4NTR SOIC
BQ4845S-A4NTRG4 SOIC
BQ4845S-A4TR SOIC
BQ4845S-A4TRG4 SOIC




BQ4845 Pinout, Pinouts
BQ4845 pinout,Pin out
This is one package pinout of BQ4845,If you need more pinouts please download BQ4845's pdf datasheet.

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