DS1302ZN/T&R

Overview

The DS1302ZN+T&R is a Real-Time Clock (RTC) IC manufactured by Analog Devices Inc./Maxim Integrated. It provides timekeeping functions including seconds, minutes, hours, date, month, day of the week, and year with leap-year compensation valid up to 2100. The device features 31 bytes of battery-backed static RAM and communicates via a simple 3-wire serial interface (CE, I/O, SCLK). Operating on a supply voltage of 2V to 5.5V, it supports both 12-hour and 24-hour formats. Key electrical parameters include a timekeeping current of 0.3µA to 1µA at 2V to 5V and an operating temperature range of -40°C to +85°C.

Feature Summary

• Real-time clock/calendar with automatic end-of-month adjustment and leap-year correction through 2100
• 31-byte battery-backed general-purpose static RAM for data storage
• Simple 3-wire synchronous serial interface compatible with most microcontrollers
• Programmable trickle charger for backup power source maintenance

Applications

• Clock and timing systems in embedded devices
• Data logging equipment requiring precise timestamping
• Industrial control panels needing reliable timekeeping
• Portable instruments with low-power requirements

Procurement Notes

Verify that the specific part number DS1302ZN+T&R corresponds to the industrial temperature grade (-40°C to +85°C) and the 8-SOIC (150 mils) package width as defined in the manufacturer's ordering information. Confirm the Tape & Reel packaging format matches production line requirements. Ensure compatibility with the system's voltage levels, noting TTL compatibility at 5V operation.

Selection Notes

Select this component when a low-cost, low-power RTC with a simple serial interface is required instead of I2C or SPI protocols. It is suitable for applications where GPIO availability is limited but three pins can be dedicated to CE, SCLK, and I/O. Consider the trickle charger feature if a rechargeable backup source is used. Verify crystal selection specifications, specifically the 6pF load capacitance requirement, for accurate timing performance.

Part Context

The DS1302 series serves as a successor to the DS1202, offering enhanced features such as dual power pins for primary and backup supplies and programmable trickle charging. The 'ZN' suffix indicates the industrial temperature range variant packaged in an 8-pin SOIC with 150 mils width. The '+T&R' designation specifies a lead-free/RoHS-compliant device supplied in a tape and reel configuration for automated assembly.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.