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Product Detailed Parameters
- Description：IC RTC CLOCK/CALENDAR PAR 24DIP
- Series：-
- Package：Tube
- Mfr：Texas Instruments
- Type：Clock/Calendar
- Features：Alarm, Daylight Savings, Leap Year, NVSRAM, Square Wave Output
- Memory Size：242B
- Time Format：HH:MM:SS (12/24 hr)
- Date Format：YY-MM-DD-dd
- Interface：Parallel
- Voltage - Supply：4.5V ~ 5.5V
- Voltage - Supply, Battery：-
- Current - Timekeeping (Max)：-
- Operating Temperature：0°C ~ 70°C
- Mounting Type：Through Hole
- Package / Case：24-DIP Module (0.61", 15.49mm)
- Supplier Device Package：24-DIP Module
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Overview
The BQ3287EAMT is a CMOS real-time clock module designed for IBM AT-compatible systems. It integrates a time-of-day clock, 100-year calendar with leap-year adjustment, and 242 bytes of nonvolatile storage. The device features an integral lithium cell and crystal, eliminating external components. Key electrical parameters include a 5V supply voltage (4.5V to 5.5V), 160 ns cycle time, and better than one minute per month accuracy. It provides three maskable interrupts, a programmable square wave output, and a 32.768kHz output for power management.
Feature Summary
- Integrated 242-byte nonvolatile RAM and internal coin cell/crystal
- Functionally compatible with DS1287/DS1287A and MC146818A/B
- Supports 12/24-hour formats and daylight saving adjustments
- Includes alarm interrupt active in battery-backup mode
Applications
- IBM AT-compatible computer systems
- Microprocessor peripheral timing applications
- Battery-backed data retention modules
Procurement Notes
Verify component status as the BQ3287EAMT is listed as obsolete by Texas Instruments. Confirm availability through lifetime-buy periods or authorized distributors if sourcing for existing designs. Ensure compatibility with legacy system requirements before procurement.
Selection Notes
Select the BQ3287EA variant over the standard BQ3287E if the application requires a dedicated RAM clear input on pin 21. Verify that the 5V logic levels and 24-pin DIP module package fit the target PCB layout. Consider the commercial temperature range (0°C to +70°C) against environmental constraints.
Part Context
This module serves as a direct replacement for older RTC chips like the DS1287 and MC146818. It simplifies design by integrating the backup power source and oscillator internally. The device maintains clock data during power failures using the internal lithium cell, ensuring continuous timekeeping without external battery connections.
Replacement Considerations
The BQ3287EAMT is marked as obsolete. Designers should evaluate newer Texas Instruments RTC solutions or verify if the BQ3285E series offers a suitable alternative for new projects, noting differences in pin accessibility for battery and crystal components.
