DS14285SN+T&R

Real Time Clock Overview

The DS14285SN+T&R is a real-time clock (RTC) and nonvolatile RAM controller in a 24-pin SOIC package. It provides timekeeping for seconds, minutes, hours, days, dates, months, and years with leap year compensation valid to 2100. The device features a multiplexed address/data bus compatible with Intel or Motorola timing standards. It includes 114 bytes of general-purpose nonvolatile RAM and 14 bytes of control registers. The unit operates at a nominal 5V supply voltage and supports an industrial temperature range of -40°C to +85°C.

Real Time Clock Feature Summary

• Direct replacement for IBM AT computer clock/calendar functions
• Multiplexed bus interface supporting Intel and Motorola timing modes
• Automatic backup supply switching and write protection for external SRAM
• Programmable square wave output and three software-maskable interrupts

Real Time Clock Applications

• IBM AT compatible system clock/calendar implementations
• Industrial systems requiring nonvolatile memory control during power failures
• Embedded controllers needing precise timekeeping with daylight saving time options

Real Time Clock Procurement Notes

Verify the ordering suffix T&R confirms tape and reel packaging. Confirm the SN designation indicates the industrial temperature grade (-40°C to +85°C). Ensure the '+' suffix denotes RoHS compliance. Cross-reference the specific lot date code against current manufacturing status as this component family may have limited availability.

Real Time Clock Selection Notes

Select this part when a direct pin-compatible upgrade from DS1285/DS1287 is required. Choose the SN variant over S if operation below 0°C is necessary. Verify that the host system supports the multiplexed bus protocol. Ensure the external crystal load capacitance matches the internal oscillator requirements of 6 pF.

Real Time Clock Part Context

This component belongs to the DS14285 series, designed as successors to the industry-standard DS12885 and DS12887. It integrates RTC functionality with NVSRAM control capabilities. The SN+T&R variant specifically combines the industrial temperature rating with surface-mount tape and reel packaging for automated assembly processes.

Real Time Clock Replacement Considerations

Public confirmed substitute: DS1685S-5+. This alternative offers similar RTC and NVSRAM control features in a 24-SOIC package but operates on a 2.7V to 3.7V supply instead of 5V.