DS1302Z/T&R

Overview

The DS1302Z/T&R is a real-time clock 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 includes 31 bytes of battery-backed static RAM for general-purpose data storage. It communicates via a simple 3-wire serial interface compatible with most microcontrollers. Operating on a supply voltage range of 2V to 5.5V, it features low power consumption, drawing less than 300nA at 2.0V. The component is housed in an 8-SOIC package (150 mils width) and operates within a commercial temperature range of 0°C to +70°C.

Feature Summary

• Real-time clock/calendar with leap-year compensation valid through 2100
• 31-byte battery-backed static RAM for non-volatile data storage
• Simple 3-wire synchronous serial interface (CE, I/O, SCLK)
• Programmable trickle charger for backup battery or supercapacitor charging

Applications

• Embedded systems requiring precise timekeeping
• IoT devices needing low-power clock management
• Data logging equipment with timestamp requirements
• Portable electronics utilizing battery backup

Procurement Notes

Verify that the specific order suffix corresponds to the Tape & Reel (TR) packaging format as indicated by the model designation. Confirm the operating temperature grade matches the application requirements, as industrial variants (-40°C to +85°C) exist under different part numbers such as DS1302ZN+. Ensure compatibility with the host microcontroller's voltage levels for the 3-wire serial interface.

Selection Notes

Select this component when a low-pin-count serial RTC is required alongside small amounts of non-volatile memory. The DS1302Z+ variant is suitable for commercial applications operating between 0°C and +70°C. For environments requiring wider temperature ranges, consider the industrial grade DS1302ZN+. The trickle charger feature allows direct connection to rechargeable backup sources without external diodes, simplifying the design.

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 'Z' suffix denotes the 8-pin SOIC package with a 150-mil width, while the '+' indicates lead-free/RoHS compliance. The '/T&R' specifies the tape and reel packaging configuration for automated assembly.

Replacement Considerations

Direct replacements include other DS1302 variants with different packages or temperature grades, such as DS1302S+ (SOIC 208 mil) or DS1302ZN+ (Industrial Temp). Note that interfaces differ significantly from I2C-based RTCs like the DS1307; pinout and software drivers are not directly compatible.