P4SMA540C Equivalent & Substitute Parts

Part Overview

The P4SMA540C is a Transient Voltage Suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose overvoltage protection in surface-mount applications. This component features a 486V reverse standoff voltage with 777V maximum clamping voltage and 500mA peak pulse current capability in a DO-214AC (SMA) package. The P4SMA540C is classified as obsolete, making identification of active equivalent parts essential for ongoing design support and procurement.

Substiute Parts

P4SMA540C

Littelfuse Inc.In Stock: 1093P4SMA540C Datasheet

Current PartRFQ

P4SMA540CA

Littelfuse Inc.In Stock: 18206P4SMA540CA Datasheet

MFR RecommendedRFQ

P4SMA540CA

Littelfuse Inc.In Stock: 18206P4SMA540CA Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the P4SMA540C is determined by the following critical electrical and mechanical parameters:

Electrical Compatibility Criteria:

• Reverse Standoff Voltage: 486V (must match)
• Peak Pulse Current: 500mA (must match)
• Power - Peak Pulse: 400W (must match)
• Package / Case: DO-214AC, SMA (must match)
• Operating Temperature Range: -65°C ~ 150°C (must match)
• Bidirectional Channels: 1 (must match)

Allowable Variation:

• Voltage - Clamping (Max) @ Ipp: May vary within the same product series while maintaining functional protection characteristics
• Voltage - Breakdown (Min): May vary within acceptable tolerance bands for the same voltage class

The P4SMA540CA qualifies as a direct substitute based on identical reverse standoff voltage, peak pulse current, power rating, package type, and operating temperature range. The clamping voltage difference (740V vs. 777V) represents a tighter clamping specification, which is acceptable for general-purpose protection applications.

Parameter Comparison

Engineering Selection Recommendations

The P4SMA540CA is the manufacturer-recommended substitute for the obsolete P4SMA540C. Both components maintain identical electrical specifications for reverse standoff voltage, peak pulse current, and power dissipation. The P4SMA540CA offers the advantage of active product status, ensuring continued availability and manufacturing support.

The P4SMA540CA exhibits a lower maximum clamping voltage (740V versus 777V), which represents improved clamping performance and is functionally compatible with applications designed for the P4SMA540C. Both parts maintain ROHS3 compliance and identical moisture sensitivity ratings, supporting equivalent reliability in production environments.

For new designs or ongoing procurement, the P4SMA540CA is the appropriate selection due to its active status and full compliance with the same regulatory and environmental standards as the original part.

Frequently Asked Questions (FAQ)

Q: Can the P4SMA540CA be used as a direct replacement for the P4SMA540C?

A: Yes. Both parts share identical reverse standoff voltage (486V), peak pulse current (500mA), power rating (400W), and DO-214AC package specification. The P4SMA540CA is the manufacturer-recommended substitute.

Q: What is the significance of the different clamping voltages (777V vs. 740V)?

A: The clamping voltage represents the maximum voltage across the diode during a transient event. The P4SMA540CA's lower clamping voltage (740V) indicates tighter voltage regulation during protection events, which is acceptable and often beneficial for sensitive circuit protection.

Q: Are there any packaging or mounting differences between these parts?

A: No. Both the P4SMA540C and P4SMA540CA use identical DO-214AC (SMA) surface-mount packaging and are compatible with the same PCB layouts and reflow processes.

Q: Why is the P4SMA540C classified as obsolete?

A: Product obsolescence typically results from manufacturer discontinuation decisions. The P4SMA540CA represents the active continuation of this protection function within the P4SMA series.

Q: Are both parts RoHS compliant?

A: Yes. Both the P4SMA540C and P4SMA540CA are ROHS3 compliant and maintain MSL 1 (Unlimited) moisture sensitivity ratings.

Q: What applications are these TVS diodes suitable for?

A: Both parts are specified for general-purpose transient voltage suppression applications requiring 486V reverse standoff protection with 500mA peak pulse current capability.