DS14285N+

Real Time Clock Overview

The DS14285N+ is a real-time clock (RTC) with nonvolatile RAM control, designed as a direct replacement for IBM AT computer clocks. It operates within an industrial temperature range of -40°C to +85°C and requires a single 5.0V supply. The device integrates a 100-year calendar, alarm functionality, and 114 bytes of general-purpose RAM. It utilizes a multiplexed address/data bus interface for pin efficiency. The component supports binary or BCD time formats and includes features such as leap year compensation valid up to the year 2100 and optional daylight saving time adjustments.

Real Time Clock Feature Summary

• Multiplexed bus interface compatible with Intel and Motorola timing standards
• Automatic backup supply switching and write protection for external SRAM
• Counts seconds, minutes, hours, days, date, month, and year with leap year compensation
• Three software-maskable interrupt sources: Time-of-Day Alarm, Periodic Rates, and End of Clock Update

Real Time Clock Applications

• IBM AT computer clock/calendar systems
• Industrial systems requiring nonvolatile memory control
• Battery-backed real-time clock applications

Real Time Clock Procurement Notes

Verify the specific package variant required, as the N suffix denotes the industrial temperature grade (-40°C to +85°C). Confirm lead-free/RoHS compliance status via the datasheet, as indicated by the '+' suffix. Ensure external components match the specified load capacitance for crystal operation.

Real Time Clock Selection Notes

Select the DS14285N+ when an industrial temperature range is required compared to the commercial DS14285. This model uses a 24-pin DIP package. If surface mount packaging is needed, consider the SN variant. Ensure the system design accommodates the multiplexed bus timing requirements for AS, DS, and CS signals.

Real Time Clock Part Context

The DS14285 series is functionally compatible with the earlier DS1285 and DS1287 models. The DS14285N+ specifically provides the same functionality in an industrial temperature grade package. It serves as a standalone RTC solution that manages external SRAM nonvolatility through its VCCO and CEO pins during power failures.

Real Time Clock Replacement Considerations

DS14285N is the non-RoHS equivalent with identical electrical specifications and temperature range.