RTC-4574SA:B0 Equivalent & Substitute Parts

Part Overview

The RTC-4574SA:B0 is a Real Time Clock (RTC) IC manufactured by EPSON, designed for clock/calendar applications with 3-Wire Serial interface. This component provides timekeeping functionality with alarm and leap year support across a wide supply voltage range of 1.6V to 5.5V. The part is currently classified as obsolete, making equivalent and substitute parts necessary for ongoing system support and new design implementations. Substitute parts must maintain functional compatibility through matching interface protocols, time/date format support, and operating temperature ranges.

Substiute Parts

RTC-4574SA:B0 ROHS

EPSONIn Stock: 993RTC-4574SA:B0 ROHS Datasheet

Current PartRFQ

DS1302S+

Analog Devices Inc./Maxim IntegratedIn Stock: 1952DS1302S+ Datasheet

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DS1343E-3+

Analog Devices Inc./Maxim IntegratedIn Stock: 945DS1343E-3+ Datasheet

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DS1344D-33+T&R

Analog Devices Inc./Maxim IntegratedIn Stock: 8268DS1344D-33+T&R Datasheet

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DS1344E-3+

Analog Devices Inc./Maxim IntegratedIn Stock: 1974DS1344E-3+ Datasheet

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DS1392U-33+

Analog Devices Inc./Maxim IntegratedIn Stock: 1081DS1392U-33+ Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution logic for the RTC-4574SA:B0 is based on the following critical parameters:

Primary Compatibility Criteria:

• Interface Protocol: 3-Wire Serial (required for direct pin-level compatibility)
• Time Format: HH:MM:SS with 24-hour support
• Date Format: YY-MM-DD-dd
• Features: Alarm and Leap Year support
• Operating Temperature Range: -40°C ~ 85°C minimum
• Supply Voltage Overlap: Minimum 1.6V to 5.5V range

Substitute Categories:

Group 1 - Direct 3-Wire Serial Interface Substitutes:

• DS1302S+ (Analog Devices Inc./Maxim Integrated)
• DS1392U-33+ (Analog Devices Inc./Maxim Integrated)

These parts maintain the 3-Wire Serial interface protocol and support the required time/date formats with alarm and leap year functionality. Both operate across the -40°C ~ 85°C temperature range.

Group 2 - SPI Interface Substitutes (Interface Change Required):

• DS1343E-3+ (Analog Devices Inc./Maxim Integrated)
• DS1344D-33+T&R (Analog Devices Inc./Maxim Integrated)
• DS1344E-3+ (Analog Devices Inc./Maxim Integrated)

These parts provide equivalent clock/calendar functionality with alarm and leap year support but use SPI interface instead of 3-Wire Serial. System-level interface adaptation is required for implementation.

Parameter Comparison

Engineering Selection Recommendations

For Direct Interface Replacement (3-Wire Serial):

DS1302S+ is suitable for applications requiring minimal system redesign. This part maintains 3-Wire Serial protocol compatibility and supports required time/date formats with alarm and leap year functionality. However, the operating temperature range is limited to 0°C ~ 70°C, which does not cover the full -40°C ~ 85°C range of the original part. This part is active and ROHS3 compliant.

DS1392U-33+ provides full operating temperature range coverage (-40°C ~ 85°C) and maintains 3-Wire Serial interface compatibility. This part includes additional features such as square wave output and trickle-charger functionality. Supply voltage minimum is 2.97V, which is higher than the original 1.6V specification. This part is active and ROHS3 compliant.

For SPI Interface Implementation (Requires System Adaptation):

DS1343E-3+ and DS1344E-3+ both use SPI interface and provide extended memory (96B NVRAM) compared to the original part. Both support the full -40°C ~ 85°C operating temperature range and include alarm, leap year, square wave output, and trickle charger features. These parts are active and ROHS3 compliant.

DS1344D-33+T&R uses SPI interface in a 14-WFDFN package with exposed pad. This part supports the full operating temperature range and includes equivalent features. Packaging is supplied in Tape & Reel format. This part is active and ROHS3 compliant.

Compliance Considerations:

All substitute parts are ROHS3 compliant and carry EAR99 ECCN classification matching the original part. All substitute parts are currently in active production status, ensuring long-term availability and supply chain stability.

Frequently Asked Questions (FAQ)

Q: Can DS1302S+ directly replace RTC-4574SA:B0 without PCB modifications?

A: DS1302S+ maintains 3-Wire Serial interface compatibility and supports the same time/date formats. However, the operating temperature range is limited to 0°C ~ 70°C versus the original -40°C ~ 85°C. Package differences (8-SOIC versus 14-SOIC) require PCB layout changes. Verify your application's temperature requirements before selection.

Q: What is the primary difference between 3-Wire Serial and SPI substitute groups?

A: 3-Wire Serial substitutes (DS1302S+, DS1392U-33+) maintain the original interface protocol and require minimal firmware changes. SPI substitutes (DS1343E-3+, DS1344D-33+T&R, DS1344E-3+) require system-level interface adaptation but offer extended memory and additional features. Interface selection depends on your system architecture and available microcontroller resources.

Q: Does DS1392U-33+ support the full 1.6V minimum supply voltage of the original part?

A: No. DS1392U-33+ has a minimum supply voltage of 2.97V, which is higher than the original 1.6V specification. If your application requires operation below 2.97V, this part is not suitable. DS1302S+ has a minimum of 2V, also exceeding the original specification.

Q: Are all substitute parts available in the same package as RTC-4574SA:B0?

A: No. The original part uses 14-SOIC packaging. Substitute parts use different packages: DS1302S+ (8-SOIC), DS1392U-33+ (10-TFSOP/10-MSOP), DS1343E-3+ (20-TSSOP), DS1344D-33+T&R (14-WFDFN), and DS1344E-3+ (20-TSSOP). PCB redesign is required for any substitute implementation.

Q: Which substitute part has the lowest timekeeping current consumption?

A: DS1302S+ specifies 0.3µA ~ 1µA @ 2V ~ 5V, which is lower than the original part's 1µA ~ 2µA @ 3V ~ 5V. DS1343E-3+ and DS1344E-3+ do not specify maximum timekeeping current. DS1344D-33+T&R specifies 120µA ~ 160µA, which is significantly higher.

Q: Can SPI substitute parts be used in applications designed for 3-Wire Serial?

A: SPI substitutes require firmware and potentially hardware modifications to support the different serial protocol. Direct pin-level substitution is not possible. System redesign is necessary to implement SPI communication.

Q: Are all substitute parts ROHS compliant?

A: Yes. All substitute parts listed are ROHS3 compliant, matching the compliance status of the original RTC-4574SA:B0.