DS1302SN

Overview

The DS1302SN+ is a Real-Time Clock (RTC) and calendar integrated circuit manufactured by Analog Devices Inc./Maxim Integrated. It provides seconds, minutes, hours, date, month, day of the week, and year information with leap-year compensation valid up to the year 2100. The device features 31 bytes of battery-backed static RAM and communicates via a simple 3-wire serial interface compatible with most microcontrollers. Operating on a supply voltage range of 2V to 5.5V, it supports both 12-hour and 24-hour time formats. The industrial temperature grade version operates from -40°C to +85°C in an 8-pin SOIC package.

Feature Summary

• Real-time clock/calendar with leap-year compensation valid through 2100
• 31-byte battery-backed general-purpose RAM
• Simple 3-wire synchronous serial interface (CE, I/O, SCLK)
• Low power operation: less than 300nA at 2.0V

Applications

• Portable instruments requiring precise timekeeping
• Telecommunication equipment
• Industrial control systems operating in wide temperature ranges
• Battery-powered embedded devices

Procurement Notes

Verify the specific suffix 'SN' indicates the industrial temperature range (-40°C to +85°C) and 8-pin SOIC (208 mils) package as defined in the manufacturer's ordering information. Confirm RoHS compliance status based on the '+' designation in the part number. Ensure the required operating environment matches the specified temperature limits for reliable performance.

Selection Notes

Select this component when an industrial temperature range is required alongside low-power RTC functionality. The DS1302SN+ differs from commercial variants (e.g., DS1302S+) by its extended temperature rating. Ensure the design accommodates the 3-wire serial interface timing requirements and utilizes a 32.768kHz crystal with a 6pF load capacitance for accurate timekeeping.

Part Context

The DS1302 series serves as a successor to the DS1202, adding dual power pins for primary and backup supplies and a programmable trickle charger. The 'SN' variant specifically denotes the industrial grade within the SOIC package family. This model is designed to minimize space requirements while providing comprehensive timekeeping and data storage capabilities for microprocessor-based systems.

Replacement Considerations

Direct replacements include other DS1302 variants such as DS1302ZN+ (commercial temp, 150mil SOIC) or DS1302N+ (industrial temp, DIP-8). Verify pin compatibility and package dimensions when substituting. Ensure the replacement part supports the required voltage range and interface protocol.