DS1307ZN+

Real Time Clock Overview

The DS1307ZN+ is a low-power, full binary-coded decimal (BCD) real-time clock and calendar integrated circuit manufactured by Analog Devices Inc./Maxim Integrated. It includes 56 bytes of battery-backed NV SRAM and communicates via an I2C bidirectional serial bus. The device tracks seconds, minutes, hours, day, date, month, and year with automatic leap-year compensation valid through 2100. Operating within a supply voltage range of 4.5V to 5.5V, it supports both 12-hour and 24-hour formats. The industrial temperature variant functions reliably between -40°C and +85°C in an 8-pin SOIC package.

Real Time Clock Feature Summary

• I2C Serial Interface: Communicates using standard I2C protocol at up to 100kHz clock frequency.
• Automatic Calendar Management: Handles variable month lengths and leap years automatically.
• Low Power Battery Backup: Consumes less than 500nA in backup mode with the oscillator running.
• Power-Fail Detection: Automatically switches to VBAT when VCC drops below 1.25 x VBAT.

Real Time Clock Applications

• Industrial control systems requiring precise timekeeping in wide temperature ranges.
• Data logging equipment needing timestamping for sensor readings.
• Embedded devices utilizing BCD-formatted time registers for simplified software handling.

Real Time Clock Procurement Notes

Verify that the specific order corresponds to the 'ZN' suffix to ensure the industrial temperature rating (-40°C to +85°C). Standard 'Z' variants are limited to commercial temperatures (0°C to +70°C). Confirm RoHS compliance status as indicated by the '+' designation in the part number. Ensure the required packaging format (tube vs. tape and reel) matches the specific suffix if ordering the T&R version.

Real Time Clock Selection Notes

Select the DS1307ZN+ over the commercial DS1307Z+ only if the application environment exceeds 70°C or drops below 0°C. The component requires an external 32.768kHz crystal with a 12.5pF load capacitance. SDA, SCL, and SQW/OUT pins require external pull-up resistors. Verify that the system logic levels are compatible with the open-drain nature of the I2C interface.

Real Time Clock Part Context

This component belongs to the DS1307 family of serial real-time clocks. The 'N' suffix specifically denotes the industrial temperature grade extension compared to the standard commercial grade. It serves as a drop-in replacement for other DS1307 variants regarding pinout and register map, provided the thermal constraints of the original design are met.

Real Time Clock Replacement Considerations

DS1307Z+ offers identical functionality but is rated for 0°C to +70°C. DS1307ZN+T&R provides the same electrical characteristics in a tape-and-reel package suitable for automated surface-mount assembly processes.