SMF22AT1G Equivalent & Substitute Parts

Part Overview

The SMF22AT1G is a unidirectional transient voltage suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose overvoltage protection in surface-mount applications. This component features a 22V reverse standoff voltage with a 35.5V maximum clamping voltage and 5.6A peak pulse current capability in a SOD-123FL package. The part is currently listed as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement.

Key Parameters

Parameter	Value
Voltage - Reverse Standoff (Typ)	22V
Voltage - Breakdown (Min)	24.4V
Voltage - Clamping (Max) @ Ipp	35.5V
Current - Peak Pulse (10/1000µs)	5.6A
Power - Peak Pulse	200W
Operating Temperature Range	-55°C ~ 150°C (TJ)
Mounting Type	Surface Mount
Package / Case	SOD-123F
Type	Zener
Unidirectional Channels	1
RoHS Status	ROHS3 Compliant
Moisture Sensitivity Level (MSL)	1 (Unlimited)

Substitute Part Grouping Explanation

Substitute parts for the SMF22AT1G are classified based on electrical parameter compatibility within the SMF series TVS diode family. The primary substitution criteria are:

Critical Parameters for Substitution:

Voltage - Reverse Standoff (Typ): 22V nominal
Voltage - Clamping (Max) @ Ipp: 35.5V nominal
Current - Peak Pulse (10/1000µs): 5.6A nominal
Power - Peak Pulse: 200W
Package / Case: SOD-123F compatible
Mounting Type: Surface Mount
Operating Temperature: -55°C ~ 150°C range
Type: Zener unidirectional

Direct Equivalents maintain identical electrical specifications and are suitable for one-to-one replacement. Functional Alternatives operate within the same voltage and power class but with different standoff voltages, requiring circuit-level compatibility verification.

Parameter Comparison

Part Number	Manufacturer	Voltage - Reverse Standoff (Typ)	Voltage - Clamping (Max) @ Ipp	Current - Peak Pulse (10/1000µs)	Power - Peak Pulse	Package / Case	Product Status
SMF22AT1G	Littelfuse Inc.	22V	35.5V	5.6A	200W	SOD-123F	Obsolete
SMF22A	MDD	22V	35.5V	5.6A	200W	SOD-123F	Active
SMF22A-T13	Littelfuse Inc.	22V	35.5V	5.6A	200W	SOD-123F	Active
SMF20A	MDD	20V	32.4V	6.2A	200W	SOD-123F	Active
SMF24A	MDD	24V	38.9V	5.1A	200W	SOD-123F	Active
SMF26A	EVVO Semi	26V	42.1V	4.8A	200W	SOD-123F	Active
SMF28A	MDD	28V	45.4V	4.4A	200W	SOD-123F	Active
SMF30A	MDD	30V	48.4V	4.1A	200W	SOD-123F	Active
SMF33A	Diotec Semiconductor	33V	53.3V	3.75A	200W	SOD-123F	Active
SMF36A	MDD	36V	58.1V	3.44A	200W	SOD-123F	Active
SMF43A	Diotec Semiconductor	43V	69.4V	2.88A	200W	SOD-123F	Active

Engineering Selection Recommendations

Direct Equivalents (Identical Electrical Specifications):

SMF22A (MDD) and SMF22A-T13 (Littelfuse Inc.) are direct functional equivalents to the SMF22AT1G. Both maintain the 22V reverse standoff voltage, 35.5V clamping voltage, and 5.6A peak pulse current. SMF22A-T13 is manufactured by the original equipment supplier (Littelfuse Inc.) and carries active product status with full ROHS3 compliance and MSL 1 rating. SMF22A from MDD offers equivalent electrical performance with active status and identical compliance certifications.

Functional Alternatives (Same Power Class, Different Voltage Ratings):

SMF20A, SMF24A, SMF26A, SMF28A, SMF30A, SMF33A, SMF36A, and SMF43A operate within the 200W power class with SOD-123F packaging but feature different reverse standoff voltages. These parts are suitable only when circuit design permits voltage rating variation. All substitute parts maintain ROHS3 compliance, MSL 1 rating (or equivalent), and -55°C to 150°C operating temperature range. All listed substitutes are in active product status with confirmed inventory availability.

Frequently Asked Questions (FAQ)

Q: Can SMF22A directly replace SMF22AT1G?

A: Yes. SMF22A from MDD provides identical electrical specifications: 22V reverse standoff, 35.5V clamping voltage, 5.6A peak pulse current, and 200W power rating in SOD-123F package. Both are ROHS3 compliant with MSL 1 rating.

Q: What is the difference between SMF22A and SMF22A-T13?

A: Both parts are electrically identical with matching voltage and current ratings. SMF22A-T13 is the Littelfuse Inc. variant (original manufacturer), while SMF22A is supplied by MDD. Selection depends on supplier availability and procurement requirements.

Q: Can I use SMF24A or SMF26A as substitutes?

A: SMF24A and SMF26A are not direct equivalents. They feature higher reverse standoff voltages (24V and 26V respectively) and different clamping voltages. Use only if circuit design accommodates these voltage variations and the application does not require the specific 22V protection threshold.

Q: Are all substitute parts available in the same package?

A: Yes. All listed substitutes use SOD-123F surface-mount packaging, ensuring mechanical and thermal compatibility with existing PCB layouts.

Q: What compliance certifications apply to substitute parts?

A: All substitute parts listed are ROHS3 compliant. Moisture sensitivity level is MSL 1 (Unlimited) for all parts except SMF33A and SMF43A, which are listed as Not Applicable. All parts carry EAR99 ECCN classification where specified.

Q: Which substitute offers the best inventory availability?

A: SMF26A (EVVO Semi) has the highest inventory level at 131,100 pieces. SMF20A (MDD) offers 91,851 pieces. SMF22A-T13 (Littelfuse Inc.) has limited availability at 872 pieces.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message