DS1302SN+

Overview

The DS1302SN+ 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. The component is housed in an 8-pin SOIC package.

Feature Summary

• Real-time clock/calendar with leap-year compensation valid through 2100
• 31-byte battery-backed NVSRAM for user data storage
• Simple 3-wire synchronous serial interface (CE, I/O, SCLK)
• Low power operation: <300nA at 2.0V; dual power pins for primary/backup switching

Applications

• Embedded systems requiring precise timekeeping
• Battery-powered devices needing low standby current
• Industrial equipment operating in wide temperature ranges (-40°C to +85°C)

Procurement Notes

Verify the specific suffix 'SN+' corresponds to the industrial temperature grade (-40°C to +85°C) and 8-SOIC (208 mils) package as defined in the manufacturer's ordering information. Confirm RoHS compliance status associated with the '+' designation. Ensure the source documentation explicitly lists this part number before procurement to avoid substitution errors with commercial grade variants.

Selection Notes

Select the DS1302SN+ when an industrial temperature range is required alongside surface-mount packaging. Compare against the DS1302S+ (commercial grade, 0°C to +70°C) if environmental conditions permit. Ensure the design accommodates the external 32.768kHz crystal requirement on pins X1 and X2. Verify that the microcontroller supports the specific 3-wire synchronous protocol timing constraints defined in the datasheet.

Part Context

The DS1302SN+ belongs to the DS1302 family of trickle-charge timekeeping chips. The 'N' suffix indicates the industrial temperature extension compared to the standard commercial version. The '+' suffix denotes lead-free/RoHS-compliant manufacturing. This model serves as a successor to earlier Dallas Semiconductor RTCs, offering enhanced low-power features and simplified serial interfacing for embedded applications.

Replacement Considerations

Direct pin-compatible replacements include other DS1302 variants such as DS1302ZN+ (commercial grade, narrower SOIC) or DS1302S+ (commercial grade). Verify temperature ratings and package dimensions (208 mils vs 150 mils) before substituting. No functional equivalents are listed in the provided documentation.