DS1302+

Overview

The DS1302+ is a 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 and communicates via a simple 3-wire serial interface compatible with most microcontrollers. Operating on a supply voltage range of 2V to 5.5V, it consumes less than 300nA at 2.0V. The component is housed in an 8-pin DIP package with a commercial operating temperature range of 0°C to +70°C.

Feature Summary

• Real-time clock/calendar with leap-year compensation valid up to 2100
• 31 bytes of battery-backed general-purpose RAM
• Simple 3-wire serial interface (CE, I/O, SCLK)
• Low power operation: <300nA at 2.0V

Applications

• Embedded systems requiring precise timekeeping
• Portable instruments and handheld devices
• Battery-powered consumer electronics

Procurement Notes

Verify that the specific order corresponds to the commercial grade variant (DS1302+) rather than the industrial grade (DS1302N+), as they differ in operating temperature specifications. Confirm the package type matches the required 8-pin DIP form factor for through-hole mounting. Ensure the ordering suffix indicates lead-free/RoHS compliance if environmental regulations apply to the assembly process.

Selection Notes

Select this component when a low-cost, single-supply or dual-supply RTC with minimal GPIO usage is required. The 3-wire interface reduces pin count compared to parallel interfaces. Consider the 0°C to +70°C commercial temperature limit; for wider environmental ranges, the industrial version (DS1302N+) is necessary. Ensure the external 32.768kHz crystal has a load capacitance of 6pF for accurate timing.

Part Context

The DS1302+ is part of the broader DS1302 family, which includes variants with different packages (SOIC) and temperature grades (Industrial). The '+' suffix denotes a lead-free and RoHS-compliant package. This specific model represents the commercial-grade version in an 8-pin DIP package, serving as a successor to earlier models like the DS1202 with added scratchpad memory and trickle-charge capabilities.

Replacement Considerations

For direct replacements within the same series, consider the DS1302N+ for industrial temperature applications (-40°C to +85°C) in the same 8-PDIP package. Surface-mount equivalents include the DS1302S+ (8-SO, 208 mils) and DS1302Z+ (8-SO, 150 mils) for commercial temperatures.