SMB8J40CA-M3/5B Equivalent & Substitute Parts

Part Overview

The SMB8J40CA-M3/5B is a bidirectional transient voltage suppressor (TVS) diode manufactured by Vishay General Semiconductor - Diodes Division. This surface mount component operates in the DO-214AA (SMB) package and is designed for general-purpose transient voltage suppression applications. The part is Active status and RoHS3 compliant. Substitute parts are necessary when primary inventory is unavailable, when alternative manufacturers are preferred for supply chain resilience, or when specific performance characteristics better match application requirements.

Key Parameters

Parameter	Value	Unit
Voltage - Reverse Standoff (Typ)	40	V
Voltage - Breakdown (Min)	44.4	V
Voltage - Clamping (Max) @ Ipp	64.5	V
Current - Peak Pulse (10/1000µs)	12.4	A
Power - Peak Pulse	800	W
Operating Temperature Range	-55 to 150	°C (TJ)
Package / Case	DO-214AA, SMB	—
Mounting Type	Surface Mount	—
RoHS Status	ROHS3 Compliant	—
Moisture Sensitivity Level (MSL)	1 (Unlimited)	—

Substitute Part Grouping Explanation

Substitute parts for the SMB8J40CA-M3/5B are grouped based on the following critical parameters that determine functional equivalence:

Primary Matching Criteria:

Voltage - Reverse Standoff (Typ): 40V
Voltage - Breakdown (Min): 44.4V
Voltage - Clamping (Max) @ Ipp: 64.5V
Current - Peak Pulse (10/1000µs): 9.3A to 12.4A
Package / Case: DO-214AA, SMB
Mounting Type: Surface Mount
Operating Temperature Range: -55°C to 150°C (or -50°C to 150°C)

Group 1 - Direct Electrical Equivalents (40V Standoff, 64.5V Clamp): These parts maintain identical reverse standoff voltage and clamping voltage specifications, ensuring drop-in compatibility for applications requiring precise voltage regulation at the 40V standoff level.

Group 2 - Higher Voltage Standoff Alternatives (43V to 48V Standoff): These parts feature elevated reverse standoff voltages (43V, 45V, 48V) with correspondingly higher clamping voltages (69.4V to 77.4V). These are suitable for applications where slightly higher transient voltage tolerance is acceptable or required.

Group 3 - Enhanced Current Handling (48A @ 8/20µs): The SM6T47CAY offers significantly higher peak pulse current capacity (48A) with automotive-grade qualification (AEC-Q101), suitable for high-energy transient suppression applications.

Parameter Comparison

Manufacturer Part Number	Manufacturer	Voltage - Reverse Standoff (Typ)	Voltage - Breakdown (Min)	Voltage - Clamping (Max) @ Ipp	Current - Peak Pulse	Power - Peak Pulse	Operating Temperature	Package / Case	Product Status
SMB8J40CA-M3/5B	Vishay General Semiconductor - Diodes Division	40V	44.4V	64.5V	12.4A (10/1000µs)	800W	-55 to 150°C	DO-214AA, SMB	Active
SMBJ40CA	MDD	40V	44.4V	64.5V	9.3A (10/1000µs)	600W	-50 to 150°C	DO-214AA, SMB	Active
SMBJ40CA-13-F	Diodes Incorporated	40V	44.4V	64.5V	9.3A (10/1000µs)	600W	-55 to 150°C	DO-214AA, SMB	Active
SMBJ40CA-TR	STMicroelectronics	40V	44.4V	64.5V	9.7A (10/1000µs)	600W	-55 to 150°C	DO-214AA, SMB	Active
SMBJ43CA	MDD	43V	47.8V	69.4V	8.7A (10/1000µs)	600W	-50 to 150°C	DO-214AA, SMB	Active
SMBJ45CA	MDD	45V	50V	72.7V	8.3A (10/1000µs)	600W	-50 to 150°C	DO-214AA, SMB	Active
SMBJ48CA	MDD	48V	53.3V	77.4V	7.8A (10/1000µs)	600W	-50 to 150°C	DO-214AA, SMB	Active
SM6T47CAY	STMicroelectronics	40V	44.4V	84V	48A (8/20µs)	600W	-55 to 150°C	DO-214AA, SMB	Active

Engineering Selection Recommendations

Direct Replacement (Identical Electrical Specifications): SMBJ40CA-13-F (Diodes Incorporated) and SMBJ40CA-TR (STMicroelectronics) are functionally equivalent to the SMB8J40CA-M3/5B for applications requiring 40V reverse standoff voltage and 64.5V clamping voltage. Both are Active status and RoHS3 compliant. SMBJ40CA-13-F maintains the full -55°C to 150°C operating range. SMBJ40CA-TR offers equivalent performance with STMicroelectronics manufacturing.

Reduced Current Capacity Alternative: SMBJ40CA (MDD) maintains identical voltage specifications (40V standoff, 64.5V clamp) but with reduced peak pulse current (9.3A versus 12.4A) and lower peak pulse power (600W versus 800W). This part is suitable for applications where the lower current rating is acceptable.

Higher Voltage Standoff Alternatives: SMBJ43CA, SMBJ45CA, and SMBJ48CA provide progressively higher reverse standoff voltages (43V, 45V, 48V) with correspondingly elevated clamping voltages. These are suitable for circuits requiring higher transient voltage suppression thresholds. All are Active status and RoHS3 compliant.

Enhanced Current Handling: SM6T47CAY (STMicroelectronics) offers significantly higher peak pulse current (48A at 8/20µs) with automotive-grade qualification (AEC-Q101). This part is suitable for high-energy transient suppression applications where the 40V standoff voltage is required but enhanced current capacity is necessary. Note: Clamping voltage is elevated to 84V.

Frequently Asked Questions (FAQ)

Q: Can SMBJ40CA-TR be used as a direct replacement for SMB8J40CA-M3/5B? A: Yes. Both parts share identical reverse standoff voltage (40V), breakdown voltage (44.4V), and clamping voltage (64.5V). Both are Active status, RoHS3 compliant, and packaged in DO-214AA (SMB). Operating temperature ranges are identical (-55°C to 150°C). Peak pulse current differs slightly (9.7A versus 12.4A), which may be acceptable depending on application transient energy levels.

Q: What is the difference between the SMB8J40CA-M3/5B and SM6T47CAY? A: Both maintain 40V reverse standoff voltage and are suitable for 40V protection circuits. The primary differences are: SM6T47CAY offers significantly higher peak pulse current (48A at 8/20µs versus 12.4A at 10/1000µs), higher clamping voltage (84V versus 64.5V), and includes automotive-grade qualification (AEC-Q101). SM6T47CAY is appropriate for high-energy transient suppression where enhanced current handling is required.

Q: Can SMBJ43CA, SMBJ45CA, or SMBJ48CA be used in place of SMB8J40CA-M3/5B? A: These parts have higher reverse standoff voltages (43V, 45V, 48V respectively) and higher clamping voltages (69.4V, 72.7V, 77.4V). They are not direct replacements but may be suitable for applications where the circuit can tolerate higher transient voltage thresholds. Verify that the higher clamping voltage does not exceed downstream component voltage ratings.

Q: Are all substitute parts available in the same package? A: Yes. All substitute parts listed are packaged in DO-214AA (SMB) surface mount format, ensuring mechanical and electrical compatibility with the original PCB layout.

Q: What compliance certifications apply to these parts? A: All parts are RoHS3 compliant and have Moisture Sensitivity Level (MSL) 1 (Unlimited). SM6T47CAY includes additional automotive-grade qualification (AEC-Q101). All parts are REACH Unaffected and classified as EAR99 for export control purposes.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message