Equivalent & Substitute Parts for RTC-4543SA:B0

Part Overview

The RTC-4543SA:B0 is a Real Time Clock (RTC) IC with integrated clock/calendar functionality, manufactured by EPSON. This device provides time and date tracking with a 3-wire serial interface, operating across a 2.5V to 5.5V supply range. The part is classified as obsolete, making equivalent substitutes necessary for new designs and production continuity. The RTC-4543SA:B0 is packaged in a 14-SOIC surface mount configuration with unlimited moisture sensitivity rating.

Substiute Parts

RTC-4543SA:B0 ROHS

EPSONIn Stock: 749RTC-4543SA:B0 ROHS Datasheet

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DS1302N+

Analog Devices Inc./Maxim IntegratedIn Stock: 1965DS1302N+ Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the RTC-4543SA:B0 is determined by the following critical parameters:

• Interface Type: 3-Wire Serial protocol compatibility
• Functional Features: Clock/Calendar with Leap Year support
• Voltage Supply Range: Minimum 2.5V operation capability
• Time and Date Format: HH:MM:SS (24-hour) and YY-MM-DD-dd format support
• Operating Temperature Range: -40°C to 85°C
• Timekeeping Current: Low-power operation in the 1µA to 3µA range

The DS1302N+ qualifies as a functional equivalent based on these parameters. While it differs in mounting type (through-hole versus surface mount) and package configuration (8-DIP versus 14-SOIC), it maintains electrical compatibility through identical interface protocol, overlapping voltage supply range, matching temperature specifications, and comparable timekeeping current consumption.

Parameter Comparison

Engineering Selection Recommendations

The DS1302N+ serves as the primary functional equivalent for the obsolete RTC-4543SA:B0. Selection between these parts depends on design constraints:

Electrical Compatibility: Both devices operate within overlapping voltage ranges (2V to 5.5V for DS1302N+, 2.5V to 5.5V for RTC-4543SA:B0) and share identical 3-wire serial interface protocol. The DS1302N+ demonstrates superior timekeeping current efficiency (0.3µA to 1µA versus 1µA to 3µA), reducing power consumption in battery-backed applications.

Package and Mounting Considerations: The RTC-4543SA:B0 uses surface mount technology (14-SOIC), while the DS1302N+ employs through-hole mounting (8-DIP). PCB redesign is required if maintaining the original surface mount footprint is mandatory. Conversely, through-hole mounting may be preferred for prototyping or legacy board compatibility.

Product Status and Compliance: The RTC-4543SA:B0 is obsolete, limiting long-term availability. The DS1302N+ maintains active production status with ROHS3 compliance, ensuring supply chain continuity and regulatory alignment.

Additional Functionality: The DS1302N+ includes 31 bytes of non-volatile SRAM and trickle-charger functionality, providing extended capabilities beyond the RTC-4543SA:B0 specification.

Frequently Asked Questions (FAQ)

Q: Can the DS1302N+ directly replace the RTC-4543SA:B0 without PCB modifications?

A: Electrical substitution is possible due to identical 3-wire serial interface and overlapping voltage specifications. However, physical replacement requires PCB redesign because the DS1302N+ uses 8-DIP through-hole packaging while the RTC-4543SA:B0 uses 14-SOIC surface mount packaging. Pin assignments differ between the two devices.

Q: What are the key electrical differences between these parts?

A: Both devices maintain identical operating temperature ranges (-40°C to 85°C) and support the same time/date formats. The DS1302N+ operates at a lower minimum voltage (2V versus 2.5V) and consumes less timekeeping current (0.3µA to 1µA versus 1µA to 3µA). The DS1302N+ includes 31 bytes of NVSRAM and trickle-charger functionality not present in the RTC-4543SA:B0.

Q: Is the DS1302N+ suitable for battery-backed timekeeping applications?

A: Yes. The DS1302N+ supports battery backup operation with a dedicated battery supply pin (2V to 5.5V range) and includes trickle-charger functionality. The RTC-4543SA:B0 specification does not indicate battery backup capability.

Q: What compliance certifications apply to both parts?

A: Both devices carry unlimited moisture sensitivity rating (MSL 1) and meet RoHS requirements. The DS1302N+ specifically complies with ROHS3, while the RTC-4543SA:B0 meets ROHS standards. Both are classified under ECCN EAR99 and HTSUS 8542.39.0001.

Q: Why is the RTC-4543SA:B0 listed as obsolete?

A: Obsolete status indicates the manufacturer has discontinued production. The DS1302N+ remains in active production, making it the recommended choice for new designs requiring RTC functionality with clock/calendar and 3-wire serial interface.