DS14285QN+

Real Time Clock Overview

The DS14285QN+ is a Real-Time Clock (RTC) with Non-Volatile Static RAM, manufactured by Analog Devices Inc./Maxim Integrated. It operates within an industrial temperature range of -40°C to +85°C and requires a single 5.0V supply voltage. The device utilizes a multiplexed address/data bus interface for efficient pin usage. Internal functions include a 100-year calendar with leap year compensation valid up to the year 2100, time-of-day clock, alarm, and programmable square-wave output. The component integrates 114 bytes of general-purpose nonvolatile RAM alongside 14 bytes of clock and control registers, totaling 128 accessible memory locations.

Real Time Clock Feature Summary

• Multiplexed bus interface compatible with Motorola or Intel timing via MOT pin
• Automatic backup switching and write protection for external SRAM
• Counts seconds, minutes, hours, days, date, month, and year with leap year compensation
• Supports 12-hour or 24-hour clock formats with AM/PM indication

Real Time Clock Applications

• Direct replacement for IBM AT computer clock/calendar systems
• Industrial systems requiring real-time tracking in extreme temperatures
• Embedded applications needing nonvolatile data retention during power failures

Real Time Clock Procurement Notes

Verify that the specific ordering suffix 'QN+' corresponds to the PLCC-28 package and the -40°C to +85°C industrial temperature grade. Confirm RoHS compliance status as indicated by the '+' suffix. Ensure the design accounts for the multiplexed bus requirements and external crystal connection if using the standalone version rather than the module variant.

Real Time Clock Selection Notes

Select this model when an industrial temperature range (-40°C to +85°C) is required compared to the commercial grade DS14285Q+. The 'N' suffix denotes the extended temperature capability. Choose the PLCC-28 package for surface-mount assembly. Verify compatibility with the system's bus timing (Intel vs. Motorola) as the MOT pin configuration affects signal interpretation.

Real Time Clock Part Context

The DS14285QN+ belongs to the DS14285 family, which provides industry-standard RTC functionality with added nonvolatile RAM control. It is functionally compatible with the earlier DS1285 and DS1287 models. The 'QN' designation specifically identifies the PLCC-28 package variant with industrial temperature rating, distinguishing it from DIP or SOIC packages and commercial temperature versions.

Real Time Clock Replacement Considerations

Public confirmed substitute part numbers: None.