DS1302SN/T&R Equivalent & Substitute Parts

Part Overview

The DS1302SN/T&R is a Real Time Clock (RTC) IC with integrated clock/calendar functionality, manufactured by Analog Devices Inc./Maxim Integrated. This 8-SOIC surface mount device provides 31 bytes of nonvolatile static RAM (NVSRAM), leap year support, and a trickle-charger feature. The part operates across a 2V to 5.5V supply range with minimal timekeeping current consumption.

The DS1302SN/T&R is classified as obsolete. Locating equivalent or substitute components becomes necessary for new designs, production continuity, or system upgrades where active product alternatives offer improved availability, compliance status, or extended support lifecycles.

Substiute Parts

DS1302SN/T&R

Analog Devices Inc./Maxim IntegratedIn Stock: 870DS1302SN/T&R Datasheet

Current PartRFQ

DS1302SN+T&R

Analog Devices Inc./Maxim IntegratedIn Stock: 30252DS1302SN+T&R Datasheet

DirectRFQ

RX-4571LC:B3 PURE SN

EPSONIn Stock: 2650RX-4571LC:B3 PURE SN Datasheet

MFR RecommendedRFQ

RX-4571SA:B3 PURE SN

EPSONIn Stock: 1338RX-4571SA:B3 PURE SN Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the DS1302SN/T&R is determined by the following critical parameters:

Interface Compatibility: All substitute parts must support 3-Wire Serial interface to maintain firmware and hardware compatibility with existing designs.

Voltage Operating Range: Substitute parts must operate within or encompass the 2V to 5.5V supply range. Parts with extended lower voltage support (1.6V minimum) remain compatible with designs operating at 2V and above.

Operating Temperature Range: Substitute parts must support the -40°C to 85°C operating temperature window.

Mounting Type: All candidates are surface mount devices, maintaining PCB layout compatibility.

Package Consideration: The original DS1302SN/T&R uses an 8-SOIC package. Substitute parts may use different package types (12-TFSOJ, 14-SOIC) provided the pinout and functional interface remain compatible with the application circuit.

Product Status and Compliance: Active product status and RoHS3 compliance are preferred for new designs and long-term supply assurance.

Parameter Comparison

Engineering Selection Recommendations

DS1302SN+T&R: This part is the direct functional equivalent of the DS1302SN/T&R, manufactured by the same supplier. It maintains identical electrical specifications, package footprint (8-SOIC), and feature set. The primary distinction is active product status and ROHS3 compliance, making it the preferred choice for designs requiring the original DS1302 architecture with improved supply availability and regulatory compliance.

RX-4571LC:B3 PURE SN (EPSON): This substitute operates within the required 3-Wire Serial interface and temperature range. The 12-TFSOJ package differs from the original 8-SOIC, requiring PCB layout modification. The extended voltage range (1.6V minimum) provides additional design flexibility. ROHS3 compliance and active product status support long-term availability. Time format is limited to 24-hour operation.

RX-4571SA:B3 PURE SN (EPSON): This substitute maintains the 14-SOIC package family, reducing layout redesign requirements compared to the 12-TFSOJ alternative. It supports 3-Wire Serial interface, the required temperature range, and ROHS3 compliance. Extended voltage range (1.6V minimum) is compatible with 2V to 5.5V designs. Time format is limited to 24-hour operation.

Selection between EPSON alternatives depends on package compatibility with existing PCB designs and firmware capability to operate with 24-hour time format exclusively.

Frequently Asked Questions (FAQ)

Q: Can DS1302SN+T&R be used as a direct replacement for DS1302SN/T&R?

A: Yes. DS1302SN+T&R is functionally and electrically identical to DS1302SN/T&R. Both use the same 8-SOIC package, support 3-Wire Serial interface, and operate across 2V to 5.5V. The primary difference is product status (active vs. obsolete) and RoHS compliance (ROHS3 vs. non-compliant). No circuit modifications are required.

Q: What are the key differences between the Maxim DS1302 and EPSON RX-4571 series?

A: Both families support 3-Wire Serial interface and the required -40°C to 85°C operating temperature. The DS1302 supports both 12-hour and 24-hour time formats, while RX-4571 devices operate in 24-hour format only. EPSON parts feature extended voltage range (1.6V minimum vs. 2V minimum) and alarm functionality. Package options differ: DS1302 uses 8-SOIC, while RX-4571 variants use 12-TFSOJ or 14-SOIC.

Q: Does package change from 8-SOIC to 14-SOIC require PCB redesign?

A: Yes. While both are SOIC family packages, the 14-SOIC has different pin count and spacing than 8-SOIC. PCB footprint, trace routing, and component placement must be updated. Pinout verification against the specific device datasheet is required before layout modification.

Q: Are EPSON RX-4571 parts compatible with existing DS1302 firmware?

A: Functional compatibility depends on firmware implementation. Both support 3-Wire Serial interface and identical date format (YY-MM-DD-dd). The primary firmware consideration is time format: RX-4571 operates exclusively in 24-hour format, while DS1302 supports both 12-hour and 24-hour modes. Firmware must be verified to operate with 24-hour time format if EPSON substitutes are selected.

Q: What is the significance of RoHS3 compliance for this component?

A: ROHS3 compliance indicates the part meets Restriction of Hazardous Substances Directive requirements, restricting lead, cadmium, mercury, and other hazardous materials. For new designs and applications subject to regulatory requirements, ROHS3-compliant parts (DS1302SN+T&R, RX-4571LC:B3, RX-4571SA:B3) are required. The original DS1302SN/T&R is RoHS non-compliant and unsuitable for regulated applications.

Q: Can lower voltage operation (1.6V) of EPSON parts affect existing 2V to 5.5V designs?

A: No. Extended voltage range (1.6V to 5.5V) is backward compatible with designs operating at 2V to 5.5V. The part functions correctly across the entire range. Lower minimum voltage provides additional design flexibility for future applications but does not impact existing circuits.