3KASMC20AHM3_A/H Equivalent & Substitute Parts

Part Overview

The 3KASMC20AHM3_A/H is a unidirectional Zener transient voltage suppressor (TVS) diode manufactured by Vishay General Semiconductor - Diodes Division in the PAR® series. This surface mount component operates in the DO-214AB (SMC) package and is designed for transient voltage protection applications. The part is classified as obsolete, necessitating identification of active equivalent alternatives that maintain electrical and mechanical compatibility for ongoing production and field replacement requirements.

Key Parameters

Parameter	Value	Unit
Voltage - Reverse Standoff (Typ)	20	V
Voltage - Breakdown (Min)	22.2	V
Voltage - Clamping (Max) @ Ipp	35.8	V
Current - Peak Pulse (10/1000µs)	83.8	A
Power - Peak Pulse	3000	W
Operating Temperature Range	-65 to 185	°C (TJ)
Package / Case	DO-214AB, SMC	—
Mounting Type	Surface Mount	—
Type	Zener	—
Unidirectional Channels	1	—
Grade	Automotive	—
Qualification	AEC-Q101	—
RoHS Status	ROHS3 Compliant	—
Moisture Sensitivity Level (MSL)	1 (Unlimited)	—

Substitute Part Grouping Explanation

Substitution of the 3KASMC20AHM3_A/H is determined by the following critical parameters:

Electrical Compatibility Requirements:

Voltage - Reverse Standoff (Typ): 20V
Voltage - Breakdown (Min): 22.2V
Unidirectional Channels: 1
Type: Zener

Mechanical Compatibility Requirements:

Package / Case: DO-214AB, SMC
Mounting Type: Surface Mount

Performance Envelope Parameters:

Voltage - Clamping (Max) @ Ipp: 35.8V (primary reference)
Current - Peak Pulse (10/1000µs): 83.8A (primary reference)
Power - Peak Pulse: 3000W (primary reference)

Substitute parts are grouped into two categories based on clamping voltage and peak pulse current characteristics:

Category A - Matched Clamping Voltage (35.8V): Parts with identical clamping voltage and peak pulse current specifications maintain direct functional equivalence.

Category B - Alternative Clamping Voltage (32.4V): Parts with reduced clamping voltage (32.4V) and varying peak pulse current ratings provide functional substitution within the same voltage class but with different transient energy handling characteristics.

Parameter Comparison

Part Number	Manufacturer	Voltage - Reverse Standoff (V)	Voltage - Breakdown Min (V)	Voltage - Clamping Max @ Ipp (V)	Current - Peak Pulse (A)	Power - Peak Pulse (W)	Operating Temp Range (°C)	Package	Product Status
3KASMC20AHM3_A/H	Vishay	20	22.2	35.8	83.8	3000	-65 to 185	DO-214AB (SMC)	Obsolete
3KASMC20AHM3_B/H	Vishay	20	22.2	32.4	92.6	3000	-65 to 185	DO-214AB (SMC)	Active
SMLJ20E3/TR13	Microchip Technology	20	22.2	35.8	83.8	300	-55 to 150	DO-214AB (SMC)	Active
3.0SMCJ20A-13	Diodes Incorporated	20	22.2	32.4	62.6	3000	-55 to 175	DO-214AB (SMC)	Active
5.0SMDJ20A	Taiwan Semiconductor Corporation	20	22.2	32.4	155	5000	-55 to 175	DO-214AB (SMC)	Active
5.0SMDJ20A-T7	Littelfuse Inc.	20	22.2	32.4	155	5000	-65 to 150	DO-214AB (SMC)	Active
SMCJ20A	Fairchild Semiconductor	20	22.2	32.4	46.3	1500	-55 to 150	DO-214AB (SMC)	Active
SMCJ20A-13-F	Diodes Incorporated	20	22.2	32.4	46.3	1500	-55 to 150	DO-214AB (SMC)	Active
SMCJ20A-HR	Littelfuse Inc.	20	22.2	32.4	46.3	1500	-65 to 150	DO-214AB (SMC)	Active

Engineering Selection Recommendations

For Direct Electrical Equivalence (Matched Clamping Voltage 35.8V):

SMLJ20E3/TR13 from Microchip Technology maintains identical voltage clamping and peak pulse current specifications. However, this part operates at reduced peak pulse power (300W versus 3000W) and narrower temperature range (-55 to 150°C versus -65 to 185°C). Selection of this part requires confirmation that the application does not exceed 300W peak pulse power and operates within the -55 to 150°C temperature envelope.

For Automotive-Grade Substitution:

The original 3KASMC20AHM3_A/H carries AEC-Q101 automotive qualification. Among active substitutes, 3KASMC20AHM3_B/H from Vishay maintains identical automotive grade and AEC-Q101 qualification with the same temperature range (-65 to 185°C) and peak pulse power (3000W). This part exhibits reduced clamping voltage (32.4V) and increased peak pulse current (92.6A).

For General-Purpose Applications with Extended Power Handling:

5.0SMDJ20A from Taiwan Semiconductor Corporation and 5.0SMDJ20A-T7 from Littelfuse Inc. provide increased peak pulse power (5000W) with higher peak pulse current (155A) at the same 32.4V clamping voltage. The Littelfuse variant extends the lower temperature limit to -65°C, matching the original part's lower bound.

For Standard Industrial Applications:

SMCJ20A-13-F from Diodes Incorporated and SMCJ20A-HR from Littelfuse Inc. provide active, readily available alternatives with 1500W peak pulse power and 46.3A peak pulse current. SMCJ20A-HR extends the lower temperature limit to -65°C.

All substitute parts maintain DO-214AB (SMC) package compatibility, surface mount mounting type, unidirectional Zener topology, and ROHS3 compliance with MSL 1 rating.

Frequently Asked Questions (FAQ)

Q: Can SMLJ20E3/TR13 directly replace 3KASMC20AHM3_A/H in all applications?

A: SMLJ20E3/TR13 matches the electrical specifications (20V standoff, 22.2V breakdown, 35.8V clamping, 83.8A peak pulse current) but operates at significantly reduced peak pulse power (300W versus 3000W). Substitution is valid only for applications where peak pulse power does not exceed 300W and operating temperature remains within -55 to 150°C.

Q: What is the difference between 3KASMC20AHM3_A/H and 3KASMC20AHM3_B/H?

A: Both parts are from Vishay's PAR® series with identical standoff voltage (20V), breakdown voltage (22.2V), and peak pulse power (3000W). The primary difference is clamping voltage: 3KASMC20AHM3_A/H clamps at 35.8V with 83.8A peak pulse current, while 3KASMC20AHM3_B/H clamps at 32.4V with 92.6A peak pulse current. The B/H variant is active and maintains automotive AEC-Q101 qualification.

Q: Are all substitute parts compatible with the DO-214AB (SMC) package footprint?

A: Yes. All listed substitute parts use DO-214AB (SMC) surface mount packaging and are mechanically compatible with the original part's PCB footprint.

Q: Which substitute offers the best match for automotive applications?

A: 3KASMC20AHM3_B/H from Vishay maintains AEC-Q101 automotive qualification, identical temperature range (-65 to 185°C), and identical peak pulse power (3000W) as the original part. This is the recommended substitute for automotive-grade requirements.

Q: What is the significance of the 5.0SMDJ series parts?

A: The 5.0SMDJ20A and 5.0SMDJ20A-T7 provide increased transient energy handling with 5000W peak pulse power and 155A peak pulse current at 32.4V clamping voltage. These parts are suitable for applications requiring higher energy dissipation than the original 3000W specification.

Q: Can I use SMCJ20A series parts as substitutes?

A: SMCJ20A, SMCJ20A-13-F, and SMCJ20A-HR are valid substitutes with identical voltage specifications (20V standoff, 22.2V breakdown, 32.4V clamping) but reduced power handling (1500W peak pulse, 46.3A peak pulse current). These parts are suitable for applications where the original 3000W power specification is not required.

Q: What is the impact of operating temperature range differences?

A: The original part operates from -65 to 185°C. Substitute parts vary: SMLJ20E3/TR13 operates -55 to 150°C (narrower range), while 3KASMC20AHM3_B/H maintains -65 to 185°C. For applications requiring the full -65 to 185°C range, only 3KASMC20AHM3_B/H is suitable among active alternatives.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message