DS12885TN+

Real Time Clock Overview

The DS12885TN+ is a real-time clock and calendar integrated circuit manufactured by Analog Devices Inc./Maxim Integrated. It provides timekeeping for seconds, minutes, hours, day, date, month, and year with automatic leap year compensation through 2099. The device includes 114 bytes of battery-backed static RAM and supports both Intel and Motorola bus timing modes via a multiplexed interface. It operates within a supply voltage range of 4.5V to 5.5V and features an industrial temperature rating from -40°C to +85°C. The component is housed in a 32-TQFP package.

Real Time Clock Feature Summary

• Multiplexed parallel interface supporting Intel and Motorola bus timing
• 114 bytes of nonvolatile, battery-backed static RAM
• Automatic date adjustment including leap year correction through 2099
• Programmable square-wave output and time-of-day alarm

Real Time Clock Applications

• Embedded systems requiring precise timekeeping
• Utility meters
• Security systems
• Network hubs, bridges, and routers

Real Time Clock Procurement Notes

Verify the specific suffix 'TN+' against official manufacturer documentation to confirm the exact tape and reel packaging configuration and industrial temperature grade. Ensure the external 32.768kHz crystal meets the specified load capacitance requirements for proper oscillator startup.

Real Time Clock Selection Notes

Select this component when a drop-in replacement for legacy IBM AT clock/calendar designs is required. It is suitable for applications needing direct CPU interfacing via parallel buses rather than serial interfaces like SPI or I2C. Verify that the system power supply remains stable above the power-fail threshold during normal operation.

Real Time Clock Part Context

The DS12885 family serves as a direct replacement for the older DS1285 and DS1287 models. While the DS12885T is listed as obsolete with the DS12885T+ as a substitute, the DS12885TN+ represents the active industrial-grade variant in the 32-pin TQFP package format.

Real Time Clock Replacement Considerations

The DS12885T+ is a confirmed public substitute for the standard commercial-grade version. For industrial temperature ranges, verify compatibility with other members of the DS12885 family such as the DS12885S+ or DS12885N+ depending on the required package type.