RX-4575LC:B3 Equivalent & Substitute Parts

Part Overview

The RX-4575LC:B3 is a Real Time Clock (RTC) IC with Clock/Calendar functionality manufactured by EPSON. This device operates as a 3-Wire Serial interface component in a 12-TFSOJ surface mount package (0.094", 2.40mm Width). The part is classified as Obsolete, making equivalent and substitute components necessary for new designs and production continuity. The RX-4575LC:B3 provides timekeeping with alarm and leap year capabilities across a wide supply voltage range of 1.6V to 5.5V, with minimal power consumption during timekeeping operation.

Substiute Parts

RX-4575LC:B3

EPSONIn Stock: 780RX-4575LC:B3 Datasheet

Current PartRFQ

RX-4571SA:B3 PURE SN

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

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DS1302+

Analog Devices Inc./Maxim IntegratedIn Stock: 27034DS1302+ Datasheet

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DS1302S+T&R

Analog Devices Inc./Maxim IntegratedIn Stock: 5240DS1302S+T&R Datasheet

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DS1302Z+T&R

Analog Devices Inc./Maxim IntegratedIn Stock: 20522DS1302Z+T&R Datasheet

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DS1305+

Analog Devices Inc./Maxim IntegratedIn Stock: 3751DS1305+ Datasheet

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DS1305EN+

Analog Devices Inc./Maxim IntegratedIn Stock: 3070DS1305EN+ Datasheet

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DS1344D-3+

Analog Devices Inc./Maxim IntegratedIn Stock: 2316DS1344D-3+ Datasheet

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DS1344E-3+T&R

Analog Devices Inc./Maxim IntegratedIn Stock: 2469DS1344E-3+T&R Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the RX-4575LC:B3 is determined by the following critical parameters:

Interface Compatibility: The primary substitutes maintain 3-Wire Serial interface protocol, ensuring firmware and circuit compatibility without redesign.

Supply Voltage Range: Substitute parts must operate within the 1.6V to 5.5V range or a compatible subset (2V to 5.5V minimum acceptable for most applications).

Package and Mounting Type: Surface mount packages are preferred for direct PCB replacement. Through-hole alternatives (8-DIP) are available but require board layout modification.

Operating Temperature Range: The RX-4575LC:B3 operates from -40°C to 85°C. Substitutes with matching or extended temperature ranges are acceptable.

Time and Date Format: All substitutes support HH:MM:SS (24-hour) and YY-MM-DD-dd formats, maintaining software compatibility.

Regulatory Compliance: All substitutes are ROHS3 compliant and carry EAR99 ECCN classification, matching the original part's compliance profile.

Substitutes are grouped into two categories: Direct Surface Mount Replacements (RX-4571SA:B3, DS1302S+T&R, DS1302Z+T&R) and Alternative Interface/Package Options (DS1302+, DS1305+, DS1305EN+, DS1344D-3+, DS1344E-3+T&R) for applications where package flexibility is acceptable.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Minimal Design Changes):

RX-4571SA:B3 PURE SN is the preferred substitute when package footprint modification is acceptable. This part maintains EPSON manufacturing, identical supply voltage range (1.6V ~ 5.5V), matching operating temperature (-40°C ~ 85°C), and 3-Wire Serial interface. The 14-SOIC package requires PCB layout adjustment but provides superior availability (1268 units in stock) compared to the obsolete RX-4575LC:B3.

For Surface Mount Alternatives (3-Wire Serial Protocol):

DS1302S+T&R and DS1302Z+T&R are active Analog Devices products in 8-SOIC surface mount packages. Both maintain 3-Wire Serial interface compatibility and support 12/24-hour time format. Operating temperature ranges from 0°C to 70°C, which is narrower than the original part. These options are suitable for applications not requiring the extended -40°C lower temperature limit. DS1302Z+T&R offers the smallest footprint (0.154", 3.90mm width) with highest inventory availability (20468 units).

For Through-Hole Applications:

DS1302+ in 8-DIP package is an active product for applications requiring through-hole mounting. This part maintains 3-Wire Serial interface and provides 31B NVSRAM with trickle-charger functionality. Operating temperature range is 0°C to 70°C.

For SPI Interface Applications (Design Flexibility):

DS1305EN+ and DS1344E-3+T&R support extended operating temperature (-40°C ~ 85°C) matching the original part. These parts use SPI interface instead of 3-Wire Serial, requiring firmware modification. DS1305EN+ provides 96B memory in 20-TSSOP package. DS1344E-3+T&R offers additional features including square wave output and trickle charger in the same 20-TSSOP package.

All recommended substitutes are ROHS3 compliant and carry EAR99 ECCN classification, maintaining regulatory alignment with the original RX-4575LC:B3.

Frequently Asked Questions (FAQ)

Q: Can RX-4571SA:B3 directly replace RX-4575LC:B3 without firmware changes?

A: Yes. Both parts maintain 3-Wire Serial interface, identical supply voltage range (1.6V ~ 5.5V), matching operating temperature (-40°C ~ 85°C), and support HH:MM:SS (24-hour) and YY-MM-DD-dd time/date formats. PCB layout modification is required due to package change from 12-TFSOJ to 14-SOIC.

Q: What is the key difference between DS1302 variants (DS1302+, DS1302S+T&R, DS1302Z+T&R)?

A: All three maintain 3-Wire Serial interface and 31B NVSRAM. DS1302+ uses 8-DIP through-hole package. DS1302S+T&R and DS1302Z+T&R are surface mount 8-SOIC variants with different physical dimensions (0.209" vs 0.154" width). Operating temperature is 0°C to 70°C for all three, narrower than the original part's -40°C to 85°C range.

Q: Why do DS1305 and DS1344 parts use SPI interface instead of 3-Wire Serial?

A: DS1305 and DS1344 families are designed for applications requiring higher memory capacity (96B vs no specified memory for RX-4575LC:B3) and additional features such as square wave output and trickle charger. SPI interface requires firmware modification but provides enhanced functionality. These parts are suitable only for designs where interface change is acceptable.

Q: Which substitute offers the best low-power timekeeping performance?

A: DS1302 variants (DS1302+, DS1302S+T&R, DS1302Z+T&R) provide the lowest timekeeping current at 0.3µA minimum @ 2V, compared to RX-4575LC:B3 at 0.7µA minimum @ 3V. However, operating temperature is limited to 0°C to 70°C. RX-4571SA:B3 provides comparable performance (0.95µA ~ 1µA) with extended temperature range (-40°C ~ 85°C).

Q: Are all substitutes ROHS3 compliant?

A: Yes. All listed substitute parts are ROHS3 compliant and carry EAR99 ECCN classification, matching the regulatory profile of the original RX-4575LC:B3.

Q: What packaging options are available for surface mount applications?

A: Surface mount options include 14-SOIC (RX-4571SA:B3), 8-SOIC (DS1302S+T&R, DS1302Z+T&R), 14-WFDFN (DS1344D-3+), and 20-TSSOP (DS1305EN+, DS1344E-3+T&R). Package selection depends on PCB layout constraints and available board space.

Q: Can DS1302+ (8-DIP) be used in a design originally using RX-4575LC:B3 (surface mount)?

A: DS1302+ maintains 3-Wire Serial interface and firmware compatibility but requires board redesign for through-hole mounting. This option is suitable only when PCB layout modification is feasible and through-hole mounting is preferred for mechanical or thermal reasons.