BQ4832YMA-85

Overview

The BQ4832YMA-85 is a non-volatile SRAM module integrating a real-time clock (RTC), CPU supervisor, and internal lithium battery. It provides 262,144 bits of storage organized as 32K x 8 bytes with parallel interface access. The device operates at a supply voltage of 4.5V to 5.5V with a maximum operating current of 4mA. Key features include automatic power-fail deselection, software clock calibration for ±1 minute per month accuracy, and a watchdog timer. Data retention is guaranteed for a minimum of 10 years in the absence of power.

Feature Summary

• Integrated 32K x 8 NVSRAM with RTC, CPU supervisor, and internal lithium battery
• Automatic power-fail chip deselection and write-protection for data security
• Software clock calibration capability exceeding ±1 minute per month accuracy
• Programmable watchdog timer, alarm/periodic interrupt, and battery-low warning

Applications

• Industrial control systems requiring non-volatile timekeeping
• Data logging applications needing extended battery-backed memory
• Embedded systems utilizing standard SRAM sockets for upgradeability

Procurement Notes

This component is classified as obsolete by Texas Instruments. Production has been discontinued, and it is no longer recommended for new designs. Availability is limited to existing stock or third-party distributors. Verification of authenticity and shelf life is critical due to the end-of-life status. Designers should consider alternative replacement parts for new projects.

Selection Notes

Select this module when a direct drop-in replacement for industry-standard 32K x 8 SRAMs is required alongside RTC functionality. Ensure the system supports the 32-pin DIP module form factor. Verify that the application can accommodate the specific register map for clock and control functions located at addresses 7FF0h–7FFFh. Check compatibility with the parallel interface timing requirements.

Part Context

The BQ4832YMA-85 belongs to the bq4832Y family of RTC modules. It combines static RAM technology with timekeeping capabilities in a single plastic package. The device is designed to fit into EPROM and EEPROM sockets without special write timing limitations. It serves as a bridge between traditional volatile memory solutions and modern integrated RTC chips.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. As the device is obsolete, designers must evaluate alternative NVSRAM or RTC+RAM combinations based on pinout compatibility and functional requirements.