Product Summary

The BQ4845YS-N Real-Time Clock is a low-power microprocessor peripheral that integrates a time-of-day clock, a 100-year calendar, and a CPU supervisor in a 28-pin SOIC or DIP. The BQ4845YS-N is ideal for fax machines, copiers, industrial control systems, point-of-sale terminals, data loggers, and computers. The BQ4845YS-N provides direct connections for a 32.768KHz quartz crystal and a 3V backup battery. The BQ4845YS-N contains a temperaturecompensated reference and comparator circuit that monitors the status of its voltage supply. When the BQ4845YS-N detects an out-of-tolerance condition, it generates an interrupt warning and subsequently a microprocessor reset.

Parametrics

BQ4845YS-N absolute maximum ratings: (1)VCC DC voltage applied on VCC relative to VSS: -0.3 to 7.0 V; (2)VT; (3)DC voltage applied on any pin excluding VCC relative to VSS: -0.3 to 7.0 V; (4)TOPR Operating temperature: 0 to +70 ℃; -40 to +85 ℃ Industrial; (5)TSTG Storage temperature: -55 to +125 ℃; (6)TBIAS Temperature under bias -40 to +85 ℃; (7)TSOLDER Soldering temperature: +260 ℃ For 10 seconds.

Features

BQ4845YS-N features: (1)Real-Time Clock counts seconds through years in BCD format; (2)On-chip battery-backup switchover circuit with nonvolatile control for external SRAM; (3)Less than 500nA of clock operation current in backup mode; (4)Microprocessor reset valid to VCC = VSS; (5)Independent watchdog timer with a programmable time-out period; (6)Power-fail interrupt warning; (7)Programmable clock alarm interrupt active in battery-backup mode; (8)Programmable periodic interrupt; (9)Battery-low warning.

Diagrams

BQ4845YS-N block diagram

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BQ4802LYDSH

Texas Instruments

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Data Sheet

Negotiable 
BQ4802LYDW
BQ4802LYDW

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Data Sheet

0-1: $3.96
1-25: $3.69
25-100: $3.33
100-250: $3.06
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BQ4802LYDWG4

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Data Sheet

0-1: $3.95
1-25: $3.34
25-100: $3.06
100-250: $2.79
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BQ4802LYDWR

Texas Instruments

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Data Sheet

0-695: $2.17
695-1000: $1.99
1000-2000: $1.87
BQ4802LYDWRG4
BQ4802LYDWRG4

Texas Instruments

Real Time Clock Parallel RTC

Data Sheet

0-695: $2.17
695-1000: $1.99
1000-2000: $1.87
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BQ4802LYPW

Texas Instruments

Real Time Clock Parallel RTC

Data Sheet

0-1: $3.95
1-25: $3.34
25-100: $3.06
100-250: $2.79