Equivalent & Substitute Parts for RTC-4543SA:A:PURE SN

Part Overview

The RTC-4543SA:A:PURE SN is a Real Time Clock (RTC) IC manufactured by EPSON, designed for clock/calendar applications with 3-wire serial interface capability. This component is classified as obsolete, making identification of functionally equivalent alternatives necessary for ongoing system support and new design implementations. The part operates across a 2.5V to 5.5V supply range and maintains timekeeping current consumption between 1µA and 3µA at nominal operating voltages.

Key Parameters

Parameter	RTC-4543SA:A:PURE SN
Manufacturer	EPSON
Category	Clock/Timing
Type	Clock/Calendar
Interface	3-Wire Serial
Voltage Supply Range	2.5V ~ 5.5V
Current - Timekeeping (Max)	1µA ~ 3µA @ 2V ~ 5V
Operating Temperature	-40°C ~ 85°C
Mounting Type	Surface Mount
Package / Case	14-SOIC (0.197", 5.00mm Width)
Product Status	Obsolete
RoHS Status	ROHS3 Compliant
Moisture Sensitivity Level (MSL)	1 (Unlimited)

Substitute Part Grouping Explanation

Substitution eligibility for the RTC-4543SA:A:PURE SN is determined by the following critical parameters:

Interface Type: 3-Wire Serial protocol compatibility
Voltage Supply Range: Minimum 2.5V operation capability
Operating Temperature Range: -40°C to 85°C coverage
Mounting Type: Surface Mount configuration
RoHS Compliance: ROHS3 Compliant status
Functional Category: Clock/Calendar IC classification

The DS1302SN+ meets all substitution criteria through equivalent 3-wire serial interface, overlapping voltage supply specifications (2V ~ 5.5V), matching operating temperature range, surface mount packaging, and ROHS3 compliance. Package form factor differences (14-SOIC versus 8-SOIC) require PCB layout evaluation but do not preclude functional substitution.

Parameter Comparison

Parameter	RTC-4543SA:A:PURE SN	DS1302SN+	Compatibility Notes
Manufacturer	EPSON	Analog Devices Inc./Maxim Integrated	Different manufacturers
Category	Clock/Timing	Clock/Timing	Equivalent
Type	Clock/Calendar	Clock/Calendar	Equivalent
Interface	3-Wire Serial	3-Wire Serial	Equivalent
Voltage Supply Range	2.5V ~ 5.5V	2V ~ 5.5V	DS1302SN+ extends lower limit to 2V
Current - Timekeeping (Max)	1µA ~ 3µA @ 2V ~ 5V	0.3µA ~ 1µA @ 2V ~ 5V	DS1302SN+ demonstrates lower consumption
Operating Temperature	-40°C ~ 85°C	-40°C ~ 85°C	Equivalent
Mounting Type	Surface Mount	Surface Mount	Equivalent
Package / Case	14-SOIC (0.197", 5.00mm Width)	8-SOIC (0.209", 5.30mm Width)	Different pin counts and dimensions
Product Status	Obsolete	Active	DS1302SN+ actively manufactured
RoHS Status	ROHS3 Compliant	ROHS3 Compliant	Equivalent
Moisture Sensitivity Level (MSL)	1 (Unlimited)	1 (Unlimited)	Equivalent

Engineering Selection Recommendations

The DS1302SN+ qualifies as a functional substitute for the obsolete RTC-4543SA:A:PURE SN based on matching core specifications: identical 3-wire serial interface, overlapping voltage supply range, equivalent operating temperature range, and ROHS3 compliance status. The DS1302SN+ maintains active product status with current manufacturing availability, addressing supply continuity concerns associated with the obsolete RTC-4543SA:A:PURE SN.

Pin-count and package geometry differences (14-SOIC to 8-SOIC transition) necessitate PCB redesign and firmware protocol verification. The DS1302SN+ provides additional features including leap year support, NVSRAM, and trickle-charger functionality not specified in the RTC-4543SA:A:PURE SN documentation. Lower timekeeping current consumption (0.3µA ~ 1µA versus 1µA ~ 3µA) represents an operational advantage in battery-backed applications.

Frequently Asked Questions (FAQ)

Q: Can the DS1302SN+ directly replace the RTC-4543SA:A:PURE SN without PCB modification?

A: No. The DS1302SN+ uses 8-SOIC packaging with different pin assignments compared to the 14-SOIC RTC-4543SA:A:PURE SN. PCB layout redesign and pinout remapping are required. Firmware modifications may be necessary to accommodate protocol differences.

Q: Are the 3-wire serial interfaces fully compatible between these parts?

A: Both components implement 3-wire serial interface protocols. However, specific command sets, timing requirements, and register definitions must be verified against respective datasheets before implementation.

Q: What is the significance of the voltage supply range difference (2.5V minimum versus 2V minimum)?

A: The DS1302SN+ extends operation to 2V, providing broader compatibility with lower-voltage battery-backed systems. Systems designed for 2.5V minimum operation remain compatible with both parts.

Q: Does the DS1302SN+ include battery backup capability?

A: Yes. The DS1302SN+ specifies battery supply voltage range of 2V ~ 5.5V, enabling independent timekeeping during main power loss. The RTC-4543SA:A:PURE SN battery supply specification was not provided in available documentation.

Q: What packaging considerations apply to this substitution?

A: The transition from 14-SOIC to 8-SOIC packaging reduces component footprint and pin count. This requires complete PCB redesign and may impact board space allocation. Both packages maintain surface mount compatibility.

Q: Is the DS1302SN+ suitable for designs requiring -40°C to 85°C operation?

A: Yes. The DS1302SN+ maintains the full -40°C to 85°C operating temperature range, matching the RTC-4543SA:A:PURE SN specification.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message