DS1302ZN+T&R

Overview

The DS1302ZN+T&R 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 a simple 3-wire serial interface compatible with most microcontrollers and includes 31 bytes of battery-backed static RAM for general-purpose data storage. Operating within 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 and is housed in an 8-SOIC package.

Feature Summary

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

Applications

• Embedded systems requiring precise timekeeping
• Data logging devices needing non-volatile memory
• Industrial control systems operating in wide temperature ranges
• Battery-powered consumer electronics

Procurement Notes

Verify that the specific order suffix matches the required temperature grade. The 'Z' indicates the commercial range (0°C to +70°C), while 'ZN' specifies the industrial range (-40°C to +85°C). Confirm packaging requirements such as Tape & Reel or Cut Tape availability directly with authorized distributors, as stock levels fluctuate.

Selection Notes

Select the DS1302ZN+ variant when operation in temperatures below 0°C is required. Ensure the external crystal has a specified load capacitance of 6pF to maintain clock accuracy. Verify that the host microcontroller supports the required 3-wire serial protocol and can handle the TTL-compatible logic levels at the selected supply voltage.

Part Context

This component belongs to the DS1302 series of trickle-charge timekeeping chips. The 'ZN' designation specifically identifies the industrial temperature grade (-40°C to +85°C) packaged in an 8-pin Small Outline (SO) format with a 150 mil width. The '+' suffix denotes lead-free/RoHS compliance. It serves as a successor to earlier Dallas Semiconductor RTC designs, offering enhanced power management features.

Replacement Considerations

For direct pin-to-pin replacements in the same package, consider the DS1302SN+ (commercial grade, 208 mil SOIC) or DS1302S+ (commercial grade, 208 mil SOIC). Note that these alternatives differ in operating temperature range and physical package width compared to the DS1302ZN+.