SMAJ22 Transient Voltage Suppressor (TVS) Diode – Equivalent & Substitute Parts

Part Overview

The SMAJ22 is a unidirectional Zener-type transient voltage suppressor diode manufactured by Littelfuse Inc., designed for general-purpose overvoltage protection in surface-mount applications. The device features a 22V reverse standoff voltage with a 37.28V maximum clamping voltage at peak pulse current of 11.3A, packaged in the DO-214AC (SMA) form factor.

The SMAJ22 is classified as obsolete. Identifying qualified substitute parts ensures design continuity and maintains system reliability when the original component becomes unavailable. Substitute parts must maintain electrical compatibility across critical parameters including reverse standoff voltage, clamping voltage, peak pulse current, and power dissipation, while meeting the same environmental and compliance requirements.

Key Parameters

Parameter	Value	Unit
Reverse Standoff Voltage (Typ)	22	V
Voltage - Breakdown (Min)	23.09	V
Voltage - Clamping (Max) @ Ipp	37.28	V
Current - Peak Pulse (10/1000µs)	11.3	A
Power - Peak Pulse	400	W
Operating Temperature Range	-65 to 150	°C (TJ)
Package / Case	DO-214AC, SMA	—
Type	Zener	—
Unidirectional Channels	1	—
RoHS Status	ROHS3 Compliant	—
Moisture Sensitivity Level (MSL)	1 (Unlimited)	—

Substitute Part Grouping Explanation

Substitute parts for the SMAJ22 are qualified based on the following electrical and mechanical parameters:

Critical Matching Parameters:

Reverse Standoff Voltage (Typ): 22V
Package / Case: DO-214AC, SMA
Type: Zener, Unidirectional (1 channel)
Mounting Type: Surface Mount
RoHS Status: ROHS3 Compliant
Moisture Sensitivity Level: 1 (Unlimited)

Allowable Variation Parameters:

Voltage - Clamping (Max) @ Ipp: 35.5V to 39.4V (within acceptable protection envelope)
Current - Peak Pulse (10/1000µs): 11.2A to 14.1A (equal or greater capability)
Power - Peak Pulse: 400W to 500W (equal or greater capability)
Operating Temperature Range: -65°C to -50°C minimum; 150°C to 175°C maximum

All identified substitutes maintain the same reverse standoff voltage, package form factor, and compliance certifications as the original SMAJ22, ensuring direct functional equivalence in circuit protection applications.

Parameter Comparison

Part Number	Manufacturer	Reverse Standoff (V)	Clamping Voltage @ Ipp (V)	Peak Pulse Current (A)	Power - Peak Pulse (W)	Operating Temp (°C)	Product Status
SMAJ22	Littelfuse Inc.	22	37.28	11.3	400	-65 to 150	Obsolete
SMAJ22A	MDD	22	35.5	11.3	400	-50 to 150	Active
SMAJ22A-13-F	Diodes Incorporated	22	35.5	11.2	400	-55 to 150	Active
SMAJ22A-TP	Micro Commercial Co	22	35.5	11.2	400	-55 to 175	Active
SMAJ22AE3/TR13	Microchip Technology	22	35.5	14.1	500	-65 to 150	Active
SMAJ22E3/TR13	Microchip Technology	22	39.4	12.7	500	-65 to 150	Active
TV04A220J-G	Comchip Technology	22	35.5	11.27	400	-55 to 150	Active

Engineering Selection Recommendations

All identified substitute parts are active products with ROHS3 compliance and MSL 1 rating, ensuring regulatory alignment and manufacturing availability. The following selection criteria apply:

For Direct Electrical Equivalence: SMAJ22A (MDD), SMAJ22A-13-F (Diodes Incorporated), SMAJ22A-TP (Micro Commercial Co), and TV04A220J-G (Comchip Technology) provide clamping voltages of 35.5V with peak pulse currents of 11.2A to 11.27A, representing the closest electrical match to the original SMAJ22 specification.

For Enhanced Performance Margin: SMAJ22AE3/TR13 (Microchip Technology) offers increased peak pulse current capability (14.1A) and power dissipation (500W), providing additional protection margin in high-stress applications while maintaining the 22V standoff voltage.

For Extended Temperature Range: SMAJ22A-TP (Micro Commercial Co) extends the maximum operating temperature to 175°C, suitable for applications requiring elevated thermal performance.

For Lowest Temperature Range: SMAJ22AE3/TR13 and SMAJ22E3/TR13 (both Microchip Technology) maintain the original -65°C minimum operating temperature, matching the thermal envelope of the obsolete SMAJ22.

All substitutes are packaged in DO-214AC (SMA) form factor and are available in Tape & Reel (TR) packaging for automated assembly processes.

Frequently Asked Questions (FAQ)

Q: Can SMAJ22A directly replace SMAJ22 in existing designs? A: Yes. SMAJ22A maintains the same 22V reverse standoff voltage, DO-214AC package, and electrical performance envelope. The 35.5V clamping voltage is within the acceptable protection range for applications designed for the original 37.28V specification.

Q: What is the difference between SMAJ22AE3/TR13 and SMAJ22E3/TR13? A: Both are Microchip Technology products with identical standoff voltage and package. SMAJ22AE3/TR13 provides 14.1A peak pulse current and 500W power dissipation, while SMAJ22E3/TR13 provides 12.7A peak pulse current with a higher 39.4V clamping voltage. Selection depends on whether peak current capacity or clamping voltage is the limiting design parameter.

Q: Are all substitutes available in Tape & Reel packaging? A: Yes. All identified substitutes are available in Tape & Reel (TR) packaging suitable for high-volume surface-mount assembly.

Q: Does operating temperature range affect substitution compatibility? A: Operating temperature range does not prevent substitution if the application operates within the substitute part's specified range. SMAJ22A-TP extends to 175°C maximum, while SMAJ22A operates to 150°C. Verify application requirements before selection.

Q: Are all substitutes RoHS3 compliant? A: Yes. All identified substitutes carry ROHS3 compliance certification and MSL 1 (Unlimited) moisture sensitivity rating, matching the original SMAJ22 environmental specifications.

Q: Can SMAJ22E3/TR13 be used where SMAJ22AE3/TR13 is specified? A: Both parts maintain 22V standoff voltage and DO-214AC packaging. SMAJ22E3/TR13 has a higher clamping voltage (39.4V vs. 35.5V) and lower peak pulse current (12.7A vs. 14.1A). Substitution is valid only if the application can tolerate the higher clamping voltage and does not require the higher current capacity.

Q: What is the significance of the -13-F and -TP suffixes? A: These suffixes denote packaging and tape configuration variants. Both SMAJ22A-13-F and SMAJ22A-TP are functionally equivalent with identical electrical specifications; selection is based on tape reel compatibility with assembly equipment.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message