BQ4830YMA-85 32KByte RTC Module PDIP-28 (USED)

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BQ4830YMA-85 32KByte RTC Module PDIP-28 (USED) The BQ4830YMA-85 is a compact PDIP-28 module that integrates a crystal-controlled real-time clock, power-fail control and an internal lithium backup battery with 32,768 bytes of byte-addressable nonvolatile SRAM organized as 32K×8, providing combined timekeeping and data retention in a single drop-in replacement for industry-standard 32K×8 SRAMs used in legacy and embedded systems. The module presents standard address and data bus signals for direct CPU interface and offers dual-port style clock registers that update once per second without interrupting normal SRAM access. Features Integrated 32K×8 nonvolatile SRAM with on-board real-time clock and control registers. Crystal timebase with clock/calendar in 24-hour BCD format and software clock calibration. Dual-port style clock registers that allow atomic clock updates while SRAM remains accessible. Internal lithium battery and power-fail detect circuit to automatically protect data on VCC loss. Pin-compatible with industry-standard 32K × 8 SRAMs, enabling simple retrofit into existing designs. Unlimited standard SRAM write cycles during normal operation with automatic write-protect on power-fail. Typical data retention of 10 years when battery/oscillator are enabled. Compact 28-pin DIP module for through-hole mounting and easy prototyping or board replacement. PINOUT Specifications Parameter Value Memory Organization 32,768 bytes (32K × 8) Total Bits 262,144 bits RTC Registers 8 bytes mapped at top of memory (addresses 7FF8–7FFF) Clock Format 24-hour BCD (Year, Month, Date, Day, Hours, Minutes, Seconds, Control) Interface Parallel address bus A0–A14, data bus DQ0–DQ7, control signals CE, OE, WE Power Control On-board power-fail detect and automatic deselect / write-protect on VCC drop Backup Battery Internal lithium cell; isolated during shipping and enabled on first VCC application Data Retention Minimum 10 years (typical under recommended conditions) Clock Accuracy Software calibration available; typical better than 1 minute/month after calibration Package 28-pin PDIP module Operating Voltage Standard +5V logic supply for read/write and clock operation Operating Modes Active read/write, standby, CMOS standby, battery-backup mode Applications Nonvolatile configuration and firmware storage with integrated time stamping for industrial and embedded systems. Real-time clock plus backup RAM for dataloggers, meters and instrumentation that require retained logs during power loss. Retrofits and repairs of legacy PC/embedded boards that use 32K×8 SRAM with timekeeping features. Firmware or parameter storage for appliances, POS equipment and telecommunications gear that benefit from RTC. Development and prototyping where compact RTC + SRAM module simplifies design integration. Package Contents 1x BQ4830YMA-85 32KByte RTC Module PDIP-28 (USED). Documents Datasheet BQ4830YMA