DS1742W-150

Real Time Clock Overview

The DS1742W-150+ is a year 2000-compliant real-time clock/calendar and 2k x 8 nonvolatile static RAM integrated into a single component. It operates at a nominal voltage of 3.3V within a commercial temperature range of 0°C to +70°C, housed in a 24-pin EDIP package. The device features a standard JEDEC bytewide interface where RTC registers occupy the eight top RAM locations (addresses 7F8h–7FFh). Timekeeping utilizes BCD-coded data with automatic leap year compensation valid through 2100. Factory calibration ensures quartz accuracy within ±1 minute per month at 25°C. An internal lithium energy source provides over 10 years of data retention without VCC power.

Real Time Clock Feature Summary

• Integrated NV SRAM, Real-Time Clock, Crystal, Power-Fail Control Circuit, and Lithium Energy Source
• Standard JEDEC Bytewide 2k x 8 Static RAM Pinout with RTC Registers in Top Eight Locations
• BCD Coded Century, Year, Month, Date, Day, Hours, Minutes, and Seconds with Automatic Leap Year Compensation
• Totally Nonvolatile with Over 10 Years of Operation in the Absence of Power

Real Time Clock Applications

• Systems requiring precise timekeeping and nonvolatile data storage in a compact footprint
• Industrial or commercial equipment operating within 0°C to +70°C environments
• Applications needing Y2K compliance and calendar functions up to the year 2100

Real Time Clock Procurement Notes

Verify the specific suffix (+) for lead-free/RoHS compliance status when sourcing replacements. Confirm that the 3.3V supply variant matches the system requirements, as 5V variants exist within the family. Check current availability status, as older revisions may be discontinued.

Real Time Clock Selection Notes

Select this model for applications requiring a 3.3V supply and commercial temperature range (0°C to +70°C). For industrial ranges (-40°C to +85°C), consider the DS1742-100IND+. Ensure the system accommodates the 24-pin EDIP through-hole package dimensions and standard parallel RAM timing constraints.

Real Time Clock Part Context

The DS1742 series combines RTC and NVSRAM functionalities, eliminating the need for external battery-backed memory chips. The DS1742W-150+ specifically denotes the 3.3V version with RoHS compliance. It replaces discrete RTC and battery-backed SRAM solutions, simplifying PCB layout and reducing component count in embedded systems.

Real Time Clock Replacement Considerations

Direct pin-compatible substitutes include other DS1742 variants such as DS1742W-120+ (3.3V) or DS1742-100+ (5V), provided voltage levels match. Verify that any replacement maintains the same 24-pin EDIP package and RTC register mapping.