DS1302S+T&R

Overview

The DS1302S+T&R is a Real-Time Clock (RTC) integrated circuit manufactured by Analog Devices Inc./Maxim Integrated. It provides timekeeping functions including seconds, minutes, hours, date, month, and year with leap-year compensation valid up to the year 2100. The device features a simple 3-wire serial interface for microcontroller communication and includes 31 bytes of battery-backed static RAM. Operating within a supply voltage range of 2V to 5.5V, it consumes less than 300nA at 2.0V during timekeeping. The component is housed in an 8-SOIC package (208 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 up to 2100
• 31-byte battery-backed general-purpose static RAM
• Simple 3-wire synchronous serial interface compatible with most microcontrollers
• Low power operation with current consumption under 300nA at 2.0V

Applications

• Electronic clocks and calendars
• Data logging systems requiring persistent timestamping
• Battery-powered embedded devices needing low standby current

Procurement Notes

Verify that the specific ordering suffix matches the required package dimensions and temperature grade. The 'S' designation indicates an 8-SOIC package with a 208 mil width, distinct from the 'Z' variant which uses a 150 mil width. Confirm the '+T&R' suffix aligns with the desired tape and reel packaging format for automated assembly processes.

Selection Notes

Select this component when a low-cost RTC with a minimal pin count is required. Ensure the application can accommodate the 3-wire serial protocol rather than I2C or SPI. Verify that the operating environment remains within the 0°C to +70°C commercial range; otherwise, consider the industrial grade variants such as the DS1302SN+ for -40°C to +85°C operation.

Part Context

The DS1302 series serves as a successor to earlier Dallas Semiconductor RTC models like the DS1202. It introduces dual power pins for flexible primary and backup supply configurations and adds a programmable trickle charger for maintaining backup sources. The device is widely recognized for its simplicity in interfacing with 8-bit microcontrollers while providing essential calendar and timing functions.

Replacement Considerations

For equivalent functionality in the same package, consider the DS1302S+ (Cut Tape) or DS1302SN+ (Industrial Temp). For different packages, the DS1302Z+ offers a smaller 150 mil SOIC footprint. Direct cross-references include PTI's PT7C4302.