RX-4803SA:UB3 PURE SN Real Time Clock (RTC) IC Equivalent & Substitute Parts

Part Overview

The RX-4803SA:UB3 PURE SN is an active-status Real Time Clock (RTC) IC manufactured by EPSON, designed for clock/calendar applications with SPI interface. This 14-SOIC surface mount device provides timekeeping functionality with alarm and leap year support across a wide supply voltage range of 1.6V to 5.5V. The part is ROHS3 compliant and carries unlimited moisture sensitivity rating (MSL 1), making it suitable for standard industrial and commercial applications. Equivalent and substitute parts are identified based on matching functional parameters: SPI interface, clock/calendar type, alarm capability, leap year support, compatible operating temperature range (-40°C to 85°C), and surface mount packaging with comparable form factors.

Substiute Parts

RX-4803SA:UB3 PURE SN

EPSONIn Stock: 857RX-4803SA:UB3 PURE SN Datasheet

Current PartRFQ

AB-RTCMC-32.768KHZ-EOA9-S3-DBT

Abracon LLCIn Stock: 1558AB-RTCMC-32.768KHZ-EOA9-S3-DBT Datasheet

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AB-RTCMC-32.768KHZ-ZIZE-S2-T

Abracon LLCIn Stock: 2110AB-RTCMC-32.768KHZ-ZIZE-S2-T Datasheet

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AB0815-T3

Abracon LLCIn Stock: 127337AB0815-T3 Datasheet

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DS1390U-18+

Analog Devices Inc./Maxim IntegratedIn Stock: 956DS1390U-18+ Datasheet

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M41T93RQA6F

STMicroelectronicsIn Stock: 1695M41T93RQA6F Datasheet

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MCP795W10-I/ST

Microchip TechnologyIn Stock: 1385MCP795W10-I/ST Datasheet

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PCF2123TS/1,118

NXP USA Inc.In Stock: 2045PCF2123TS/1,118 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the RX-4803SA:UB3 PURE SN are identified based on the following critical parameters that determine functional compatibility:

Primary Matching Criteria:

• Interface type: SPI
• Device type: Clock/Calendar with alarm and leap year functionality
• Operating temperature range: -40°C to 85°C
• Supply voltage overlap: Minimum 1.6V compatibility
• Surface mount packaging
• Product status: Active
• RoHS3 compliance

Substitution Logic: Parts are grouped into two categories based on package form factor compatibility:

1. 14-Pin SOIC/TSSOP Package Group (direct footprint compatibility with RX-4803SA:UB3): PCF2123TS/1,118 and MCP795W10-I/ST maintain identical or near-identical pinout and package dimensions, enabling direct board-level substitution.

2. Alternative Package Group (functional equivalence with package redesign): AB-RTCMC-32.768KHZ-EOA9-S3-DBT, AB-RTCMC-32.768KHZ-ZIZE-S2-T, AB0815-T3, DS1390U-18+, and M41T93RQA6F provide equivalent clock/calendar functionality with SPI interface but require PCB layout modification due to different package types (10-SMD Module, 16-VFQFN, 10-TFSOP, 16-VQFN).

All substitute parts maintain the core functional requirements: SPI communication protocol, real-time clock and calendar operation, alarm capability, leap year support, and operating temperature range of -40°C to 85°C.

Parameter Comparison

Engineering Selection Recommendations

Direct Substitution (No PCB Redesign Required):

PCF2123TS/1,118 (NXP USA Inc.) and MCP795W10-I/ST (Microchip Technology) are the primary direct substitutes for the RX-4803SA:UB3 PURE SN. Both parts maintain 14-pin TSSOP packaging with compatible pinout and footprint dimensions. Both are active-status products with ROHS3 compliance and MSL 1 rating. PCF2123TS/1,118 matches the supply voltage range (1.6V ~ 5.5V) identically and offers lower timekeeping current (0.33µA ~ 0.38µA @ 2V ~ 5V). MCP795W10-I/ST operates within 1.8V ~ 3.6V supply range and provides additional features including EEPROM and SRAM storage.

Functional Equivalents (PCB Layout Modification Required):

AB-RTCMC-32.768KHZ-EOA9-S3-DBT and AB-RTCMC-32.768KHZ-ZIZE-S2-T (Abracon LLC) provide clock/calendar functionality with integrated crystal modules in 10-SMD package format. AB0815-T3 (Abracon LLC) offers 256B SRAM in 16-VFQFN package with ultra-low timekeeping current (0.17µA ~ 0.22µA @ 1.8V ~ 3V) but operates within 1.7V ~ 3.6V supply range. M41T93RQA6F (STMicroelectronics) provides 7B SRAM in 16-VQFN package with 2.7V ~ 5.5V supply compatibility. DS1390U-18+ (Analog Devices Inc./Maxim Integrated) operates within narrow supply range (1.71V ~ 1.89V) and is suitable only for applications with fixed low-voltage supplies.

All substitute parts maintain active product status, ROHS3 compliance, and MSL 1 rating, ensuring equivalent reliability and regulatory compliance with the original part.

Frequently Asked Questions (FAQ)

Q: Can PCF2123TS/1,118 be used as a direct replacement for RX-4803SA:UB3 PURE SN without PCB modification?

A: Yes. Both parts use 14-pin TSSOP packaging with compatible pinout and footprint. PCF2123TS/1,118 matches the supply voltage range (1.6V ~ 5.5V) and maintains identical operating temperature range (-40°C to 85°C). SPI interface protocol and clock/calendar functionality are equivalent. Board-level substitution is possible without layout changes.

Q: What is the key difference between 14-SOIC and 14-TSSOP packages?

A: 14-SOIC (0.197", 5.00mm width) and 14-TSSOP (0.173", 4.40mm width) are both 14-pin surface mount packages with different body widths and pin pitch. While pinout may be compatible, PCB footprints differ. Direct substitution between these packages requires verification of footprint compatibility with your specific board design.

Q: Why do some substitute parts have lower timekeeping current specifications?

A: Timekeeping current varies based on internal circuit design and manufacturing process. Lower timekeeping current (e.g., AB-RTCMC-32.768KHZ-ZIZE-S2-T at 0.35µA ~ 0.4µA) indicates more efficient power consumption during battery-backed operation. This is an advantage in battery-powered applications but does not affect functional compatibility.

Q: Can AB0815-T3 be used in applications requiring 5.5V supply voltage?

A: No. AB0815-T3 operates within 1.7V ~ 3.6V supply range and is not compatible with 5.5V supplies. The RX-4803SA:UB3 PURE SN supports 1.6V ~ 5.5V. If your application requires 5.5V operation, select PCF2123TS/1,118, MCP795W10-I/ST, or AB-RTCMC-32.768KHZ-EOA9-S3-DBT instead.

Q: What does "10-SMD Module" package mean for AB-RTCMC parts?

A: 10-SMD Module indicates an integrated module package containing the RTC IC and supporting crystal oscillator on a single substrate. This differs from discrete IC packages and requires different PCB footprint design. Module packages simplify crystal integration but occupy larger board area than discrete IC packages.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All listed substitute parts carry ROHS3 compliance certification, matching the regulatory status of the RX-4803SA:UB3 PURE SN. All parts also maintain MSL 1 (unlimited) moisture sensitivity rating.

Q: Which substitute part has the lowest power consumption?

A: AB-RTCMC-32.768KHZ-ZIZE-S2-T offers the lowest timekeeping current at 0.35µA ~ 0.4µA @ 2V ~ 5V. AB0815-T3 provides 0.17µA ~ 0.22µA @ 1.8V ~ 3V but operates within narrower voltage range (1.7V ~ 3.6V).

Q: Can DS1390U-18+ be used in general-purpose applications?

A: DS1390U-18+ is limited to applications with fixed 1.71V ~ 1.89V supply voltage. The narrow supply range makes this part unsuitable for general-purpose applications requiring standard 3.3V or 5V supplies. Use this part only in specialized low-voltage systems.