SA22 Transient Voltage Suppressor (TVS) Diode - Equivalent & Substitute Parts

Part Overview

The SA22 is a unidirectional Zener-type transient voltage suppressor diode manufactured by Littelfuse, designed for general-purpose overvoltage protection applications. The device features a 22V reverse standoff voltage with a 37.28V maximum clamping voltage at peak pulse current, housed in a DO-204AC (DO-15) axial through-hole package. The SA22 is classified as obsolete; equivalent and substitute parts are available from alternative manufacturers to maintain design continuity and ensure supply chain reliability.

Key Parameters

Parameter	Value	Unit
Voltage - Reverse Standoff (Typ)	22	V
Voltage - Breakdown (Min)	23.09	V
Voltage - Clamping (Max) @ Ipp	37.28	V
Current - Peak Pulse (10/1000µs)	14.4	A
Power - Peak Pulse	500	W
Operating Temperature Range	-55 to 175	°C (TJ)
Package / Case	DO-204AC, DO-15, Axial	—
Mounting Type	Through Hole	—
Type	Zener	—
Unidirectional Channels	1	—

Substitute Part Grouping Explanation

Substitution of the SA22 is determined by strict equivalence across the following electrical and mechanical parameters:

Voltage - Reverse Standoff (Typ): 22V
Voltage - Breakdown (Min): 23.09V or higher
Current - Peak Pulse (10/1000µs): 14.4A or higher
Power - Peak Pulse: 500W
Operating Temperature Range: -55°C to 175°C (TJ)
Package / Case: DO-204AC, DO-15, Axial
Mounting Type: Through Hole
Type: Zener
Unidirectional Channels: 1

Substitute parts must maintain compatibility across all listed parameters. Clamping voltage variations within the specified range do not preclude substitution, provided all other electrical and mechanical criteria are met.

Parameter Comparison

Parameter	SA22 (Littelfuse)	SA22A (Fairchild)	SAC22 (Littelfuse)	SA22A-AP (MCC)	SA22A-BP (MCC)	SA22A-TP (MCC)
Voltage - Reverse Standoff (Typ)	22V	22V	22V	22V	22V	22V
Voltage - Breakdown (Min)	23.09V	24.4V	24.4V	24.4V	24.4V	24.4V
Voltage - Clamping (Max) @ Ipp	37.28V	35.5V	35.4V	35.5V	35.5V	35.5V
Current - Peak Pulse (10/1000µs)	14.4A	14.4A	14A	14.4A	14.4A	14.4A
Power - Peak Pulse	500W	500W	500W	500W	500W	500W
Operating Temperature Range	-55 to 175°C	-55 to 175°C	-55 to 175°C	-55 to 175°C	-55 to 175°C	-55 to 175°C
Package / Case	DO-204AC, DO-15	DO-204AC, DO-15	DO-204AC, DO-15	DO-15	DO-15	DO-15
Mounting Type	Through Hole	Through Hole	Through Hole	Through Hole	Through Hole	Through Hole
Type	Zener	Zener	Zener	Zener	Zener	Zener
Unidirectional Channels	1	1	1	1	1	1
Product Status	Obsolete	Obsolete	Active	Active	Active	Active
RoHS Status	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	Not specified	Not specified	Not specified

Engineering Selection Recommendations

All listed substitute parts meet the electrical and mechanical requirements for direct replacement of the SA22. Selection among available options should be based on the following criteria:

Active Product Status: SAC22 (Littelfuse), SA22A-AP (MCC), SA22A-BP (MCC), and SA22A-TP (MCC) are classified as active products and are recommended for new designs and long-term supply chain stability.

Compliance Certifications: All substitute parts maintain ROHS3 compliance. SAC22 and SA22A variants carry REACH Unaffected status where specified, ensuring regulatory compliance across multiple jurisdictions.

Packaging and Inventory: SAC22 is supplied in Tape & Reel (TR) format, suitable for automated assembly. SA22A variants from Micro Commercial Co are supplied in Bulk packaging. Selection should align with production volume and assembly methodology.

Clamping Voltage Variation: SA22A (Fairchild), SA22A-AP, SA22A-BP, and SA22A-TP exhibit lower maximum clamping voltages (35.4V to 35.5V) compared to the original SA22 (37.28V). This variation remains within acceptable substitution parameters for general-purpose transient suppression applications.

Frequently Asked Questions (FAQ)

Q: Can SA22A variants from Micro Commercial Co be used as direct replacements for the SA22?

A: Yes. SA22A-AP, SA22A-BP, and SA22A-TP meet all electrical and mechanical substitution criteria, including 22V reverse standoff voltage, 14.4A peak pulse current, 500W peak pulse power, and DO-15 through-hole packaging. All three variants are active products with current availability.

Q: What is the difference between SAC22 and SA22A?

A: Both are electrically equivalent substitutes for the SA22. SAC22 is manufactured by Littelfuse (the original SA22 manufacturer) and is supplied in Tape & Reel format. SAC22 carries a slightly lower peak pulse current specification (14A versus 14.4A) and a marginally lower clamping voltage (35.4V versus 35.5V). SA22A is manufactured by Fairchild Semiconductor and supplied in Bulk packaging.

Q: Is the SA22 still available?

A: The SA22 is classified as obsolete. However, 821 pieces are reported in current inventory. For new designs and long-term supply assurance, selection of an active substitute part (SAC22, SA22A-AP, SA22A-BP, or SA22A-TP) is recommended.

Q: Does the lower clamping voltage of substitute parts affect circuit performance?

A: Substitute parts exhibit clamping voltages between 35.4V and 35.5V, compared to the original SA22 at 37.28V. This represents a reduction of approximately 1.8V to 1.9V. Substitution is valid provided the circuit design accommodates this variation within the specified operating parameters.

Q: Are all substitute parts RoHS compliant?

A: Yes. All listed substitute parts are ROHS3 compliant. SAC22 and SA22A variants carry explicit REACH Unaffected status where specified, confirming compliance with European environmental regulations.

Q: What packaging formats are available for substitute parts?

A: SAC22 is supplied in Tape & Reel (TR) format for automated assembly. SA22A variants (SA22A-AP, SA22A-BP, SA22A-TP) are supplied in Bulk packaging. Selection should align with production methodology and volume requirements.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message