DS1302ZN+

Overview

The DS1302ZN+ is a low-power 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 for general-purpose data storage. Communication is handled via a simple 3-wire serial interface compatible with most microcontrollers. It operates within a supply voltage range of 2V to 5.5V and supports an industrial temperature range of -40°C to +85°C.

Feature Summary

• Real-time clock/calendar with leap-year compensation valid through 2100
• 31 bytes of battery-backed NVSRAM for general-purpose storage
• Simple 3-wire synchronous serial interface (CE, I/O, SCLK)
• Programmable trickle charger for backup power sources

Applications

• Embedded systems requiring precise timekeeping
• Data logging devices needing timestamping
• Battery-powered portable electronics
• Industrial control systems operating in wide temperature ranges

Procurement Notes

Verify that the specific order suffix 'ZN+' corresponds to the industrial temperature grade (-40°C to +85°C) and the 8-SOIC (150 mils) package as defined in the manufacturer's ordering information. Confirm RoHS compliance status if required by local regulations. Ensure the supplier provides documentation matching the exact part number to avoid confusion with commercial grade or alternative package variants.

Selection Notes

Select this component when a low-pin-count RTC with integrated non-volatile memory is required. The DS1302ZN+ is suitable for designs needing industrial temperature stability. Designers must account for the external 32.768kHz crystal requirement and ensure the microcontroller supports the specific 3-wire serial timing constraints. Verify that the system voltage remains within the 2.0V to 5.5V operational range for both primary and backup supplies.

Part Context

The DS1302 series serves as a successor to earlier Dallas Semiconductor RTC models like the DS1202. The 'Z' suffix denotes the 8-pin SOIC (150 mils) surface-mount package, while 'N' indicates the industrial temperature rating. The '+' suffix signifies lead-free/RoHS-compliant manufacturing. This variant is distinct from the DIP package versions and the commercial temperature grade parts.

Replacement Considerations

Direct pin-compatible replacements include other DS1302 variants such as DS1302SN+ (industrial, 208 mil SOIC) or DS1302ZN+T&R (tape and reel packaging). Note that interfaces differ significantly from I2C-based RTCs like the DS1307; software adaptation is required for cross-family substitution.