SA11 Transient Voltage Suppressor (TVS) Diode - Equivalent & Substitute Parts

Part Overview

The SA11 is a unidirectional Zener-type transient voltage suppressor diode manufactured by Littelfuse Inc., designed for general-purpose overvoltage protection applications. The device features an 11V reverse standoff voltage with a maximum clamping voltage of 19.11V at peak pulse current, housed in a DO-204AC (DO-15) axial through-hole package. The SA11 is classified as obsolete, necessitating identification of active equivalent and substitute parts for new designs and ongoing production requirements.

Substiute Parts

SA11

Littelfuse Inc.In Stock: 786SA11 Datasheet

Current PartRFQ

SA11A

Taiwan Semiconductor CorporationIn Stock: 300315SA11A Datasheet

DirectRFQ

5KP11A-TP

Micro Commercial CoIn Stock: 10455KP11A-TP Datasheet

MFR RecommendedRFQ

SA11A-AP

Micro Commercial CoIn Stock: 1047SA11A-AP Datasheet

MFR RecommendedRFQ

SA11A-BP

Micro Commercial CoIn Stock: 1217SA11A-BP Datasheet

MFR RecommendedRFQ

SA11A-TP

Micro Commercial CoIn Stock: 805SA11A-TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SA11 is determined by the following critical parameters:

• Voltage - Reverse Standoff: 11V (exact match required)
• Voltage - Clamping (Max) @ Ipp: 19.11V maximum (substitute must not exceed this value)
• Current - Peak Pulse (10/1000µs): 28A minimum (substitute must support this rating)
• Power - Peak Pulse: 500W minimum (substitute must support this rating)
• Mounting Type: Through Hole (mechanical compatibility)
• Package / Case: DO-204AC or DO-15 compatible (physical fit requirement)
• Operating Temperature: -55°C ~ 175°C (thermal operating range)

Substitute parts are grouped into two categories:

Category 1: Direct Electrical Equivalents - Parts with identical standoff voltage, clamping voltage, and peak pulse current specifications, maintaining the same power dissipation rating and package form factor.

Category 2: Enhanced Performance Substitutes - Parts with identical standoff and clamping voltages but higher peak pulse current and power ratings, suitable for applications requiring increased transient energy absorption while maintaining voltage regulation characteristics.

Parameter Comparison

Engineering Selection Recommendations

SA11A (Taiwan Semiconductor Corporation) - Direct electrical equivalent with active product status. Clamping voltage reduced to 18.2V (lower than original 19.11V), providing tighter voltage regulation. Identical peak pulse current and power ratings. ROHS3 compliant. Suitable for direct replacement in new designs where the lower clamping voltage is acceptable.

SA11A-AP, SA11A-BP, SA11A-TP (Micro Commercial Co) - Functionally equivalent to SA11A with identical electrical specifications. All three variants maintain 11V standoff voltage, 18.2V clamping voltage, and 28A peak pulse current. Differ only in packaging configuration (bulk vs. tape & reel). ROHS3 compliant and REACH unaffected. Selection among these three variants depends on procurement and assembly requirements.

5KP11A-TP (Micro Commercial Co) - Enhanced performance substitute with identical voltage regulation characteristics (11V standoff, 18.2V clamping) but significantly higher peak pulse current (274A) and power dissipation (5000W). Housed in R-6 package rather than DO-15. Suitable for applications requiring greater transient energy absorption while maintaining the same voltage protection threshold. ROHS3 compliant and REACH unaffected.

Frequently Asked Questions (FAQ)

Q: Can SA11A variants be used as direct replacements for SA11?

A: Yes, SA11A variants (SA11A, SA11A-AP, SA11A-BP, SA11A-TP) are direct electrical equivalents with identical standoff voltage (11V), peak pulse current (28A), and power rating (500W). The clamping voltage is slightly lower at 18.2V compared to the original 19.11V, which provides improved voltage regulation. All variants are active products with ROHS3 compliance.

Q: What is the difference between SA11A-AP, SA11A-BP, and SA11A-TP?

A: These three part numbers are functionally identical in electrical specifications. The suffix designations (AP, BP, TP) indicate different packaging or supplier configurations. Selection should be based on procurement availability and assembly process requirements (bulk vs. tape & reel packaging).

Q: When should 5KP11A-TP be selected instead of SA11A?

A: The 5KP11A-TP should be selected when the application requires higher transient energy absorption capability. It maintains identical voltage regulation (11V standoff, 18.2V clamping) but provides 274A peak pulse current and 5000W power dissipation compared to 28A and 500W for SA11A. The R-6 package differs from DO-15, requiring PCB layout verification for mechanical compatibility.

Q: Are all substitute parts ROHS3 compliant?

A: Yes, all substitute parts listed (SA11A, 5KP11A-TP, SA11A-AP, SA11A-BP, SA11A-TP) are ROHS3 compliant. The original SA11 is also ROHS3 compliant.

Q: What is the impact of the clamping voltage difference between SA11 (19.11V) and SA11A (18.2V)?

A: The lower clamping voltage of SA11A provides tighter voltage regulation, clamping transient overvoltages to a lower peak level. This is generally beneficial for circuit protection but must be verified against the protected circuit's maximum voltage tolerance to ensure no adverse effects on downstream components.

Q: Can the package be changed from DO-15 to R-6 when using 5KP11A-TP?

A: The R-6 package has different physical dimensions than DO-15. PCB layout and mechanical clearance must be verified before substitution. The axial lead configuration is compatible with through-hole assembly, but hole spacing and component height may differ.

Q: What is the operating temperature range for all substitute parts?

A: All substitute parts operate across the same temperature range as the original SA11: -55°C to 175°C (junction temperature). This ensures thermal compatibility across the full operating envelope.