NJU6355ED Equivalent & Substitute Parts

Part Overview

The NJU6355ED is a Real Time Clock (RTC) IC manufactured by Nisshinbo Micro Devices Inc., designed for clock/calendar applications with 4-wire serial interface. This device operates in the 4.5V to 5.5V supply range and provides timekeeping functionality with leap year support in a through-hole 8-DIP package.

The NJU6355ED is classified as obsolete. Identifying equivalent and substitute parts is necessary to support legacy system maintenance, design updates, and procurement continuity when original inventory becomes unavailable.

Substiute Parts

NJU6355ED

Nisshinbo Micro Devices Inc.In Stock: 2206NJU6355ED Datasheet

Current PartRFQ

RX-4045NB:AA3

EPSONIn Stock: 2108RX-4045NB:AA3 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the NJU6355ED requires evaluation based on the following critical parameters:

Functional Compatibility:

• Clock/Calendar functionality with leap year support
• Time and date format capability (HH:MM:SS and YY-MM-DD-dd)

Electrical Compatibility:

• Supply voltage range overlap or compatibility with system design
• Timekeeping current consumption within acceptable limits

Interface Compatibility:

• Serial communication protocol (4-wire serial, SPI, or equivalent)
• Pin configuration and signal compatibility

Physical Compatibility:

• Mounting type (through-hole versus surface mount affects PCB design)
• Package form factor

Regulatory Compliance:

• RoHS and REACH compliance status
• Product status (active versus obsolete)

The RX-4045NB:AA3 is identified as a substitute based on shared functional characteristics (clock/calendar with leap year), compatible time/date formats, and regulatory compliance. However, differences in interface protocol, mounting type, and package form factor require design-level evaluation.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Same PCB, No Redesign):

No direct pin-compatible substitute is available. The NJU6355ED operates on a 4-wire serial interface in a through-hole 8-DIP package. The RX-4045NB:AA3 uses SPI protocol in a surface-mount 22-LFDFN package, requiring both schematic and PCB redesign.

For New Designs or System Redesigns:

The RX-4045NB:AA3 is suitable as a functional substitute when design changes are acceptable. This part is actively supported by EPSON, offers improved specifications (lower power consumption, wider voltage and temperature ranges), and maintains RoHS3 compliance. The addition of alarm functionality provides enhanced capability beyond the original NJU6355ED.

Compliance Considerations:

Both parts meet RoHS requirements. The RX-4045NB:AA3 carries REACH Affected status, whereas the NJU6355ED is REACH Unaffected. Regulatory requirements for the target application must be evaluated.

Inventory and Availability:

The NJU6355ED (2177 pcs) and RX-4045NB:AA3 (2030 pcs) are both available in stock. The active product status of the RX-4045NB:AA3 ensures long-term availability and supply chain stability.

Frequently Asked Questions (FAQ)

Q: Can the RX-4045NB:AA3 replace the NJU6355ED without PCB modifications?

A: No. The RX-4045NB:AA3 uses SPI serial interface versus the 4-wire serial interface of the NJU6355ED, and employs surface-mount packaging versus through-hole. Both schematic and PCB redesign are required.

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

A: Both provide clock/calendar functionality with leap year support and identical date format (YY-MM-DD-dd). The RX-4045NB:AA3 adds alarm functionality and supports both 12-hour and 24-hour time formats, whereas the NJU6355ED supports 24-hour format only.

Q: Is the RX-4045NB:AA3 more power-efficient?

A: Yes. The RX-4045NB:AA3 draws 1.2µA to 1.8µA during timekeeping operation, compared to 4µA to 15µA for the NJU6355ED. This represents significant power savings in battery-backed applications.

Q: What voltage ranges do these parts support?

A: The NJU6355ED operates at 4.5V to 5.5V. The RX-4045NB:AA3 supports a wider range of 1.7V to 5.5V, enabling use in lower-voltage systems.

Q: Are both parts RoHS compliant?

A: Yes. The NJU6355ED is RoHS Compliant, and the RX-4045NB:AA3 is ROHS3 Compliant. Both meet current RoHS requirements.

Q: What is the operating temperature range for each part?

A: The NJU6355ED operates from -30°C to 80°C. The RX-4045NB:AA3 operates from -40°C to 85°C, providing a wider temperature envelope.

Q: Why is the NJU6355ED classified as obsolete?

A: Obsolete status indicates that the manufacturer has discontinued production and support. The NJU6355ED remains available in current inventory but will not receive design updates or long-term supply guarantees.

Q: Can I use the RX-4045NB:AA3 in a legacy system designed for the NJU6355ED?

A: Only with design modifications. The different interface protocol and package type require schematic redesign, firmware updates to support SPI communication, and PCB layout changes. A direct drop-in replacement is not possible.