P6SMB33 Equivalent & Substitute Parts

Part Overview

The P6SMB33 is a unidirectional Transient Voltage Suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose transient voltage protection in surface-mount applications. This component features a 28.2V reverse standoff voltage with a 47.99V maximum clamping voltage at peak pulse current of 13.3A, housed in a DO-214AA (SMB) package. The part is currently listed as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement.

Substiute Parts

P6SMB33

Littelfuse Inc.In Stock: 945P6SMB33 Datasheet

Current PartRFQ

P6SMB33A

Eaton - Electronics DivisionIn Stock: 17119P6SMB33A Datasheet

DirectRFQ

P6SMB33A

Eaton - Electronics DivisionIn Stock: 17119P6SMB33A Datasheet

DirectRFQ

SM6T33A

STMicroelectronicsIn Stock: 95374SM6T33A Datasheet

MFR RecommendedRFQ

SM6T33A-E3/52

Vishay General Semiconductor - Diodes DivisionIn Stock: 1750SM6T33A-E3/52 Datasheet

MFR RecommendedRFQ

SM6T33AY

STMicroelectronicsIn Stock: 57473SM6T33AY Datasheet

MFR RecommendedRFQ

SMBJP6KE33A-TP

Micro Commercial CoIn Stock: 2410SMBJP6KE33A-TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the P6SMB33 is determined by the following critical electrical and mechanical parameters:

Electrical Compatibility Criteria:

• Voltage - Reverse Standoff (Typ): 28.2V (must match)
• Voltage - Breakdown (Min): 29.75V minimum (must meet or exceed)
• Voltage - Clamping (Max) @ Ipp: acceptable range 45.7V to 59V
• Current - Peak Pulse (10/1000µs): 13.1A to 68A
• Power - Peak Pulse: 600W (must match)
• Type: Zener (must match)
• Unidirectional Channels: 1 (must match)

Mechanical Compatibility Criteria:

• Mounting Type: Surface Mount (must match)
• Package / Case: DO-214AA, SMB (must match)
• Operating Temperature Range: -55°C minimum to 150°C maximum (must encompass or match)

Compliance Criteria:

• RoHS Status: ROHS3 Compliant (preferred)
• Moisture Sensitivity Level (MSL): 1 (Unlimited) (preferred)

All substitute parts listed meet the core electrical and mechanical requirements for direct replacement in the P6SMB33 application circuit.

Parameter Comparison

Engineering Selection Recommendations

P6SMB33A (Eaton - Electronics Division): Active product status with standard RoHS compliance. Clamping voltage of 45.7V provides closer alignment to the original P6SMB33 specification compared to higher-clamping alternatives. Suitable for direct replacement in general telecom and industrial applications.

SM6T33A (STMicroelectronics): Active product with ROHS3 compliance. Higher peak pulse current rating of 68A (8/20µs) and clamping voltage of 59V provide enhanced transient suppression capability. Appropriate for applications requiring superior surge protection margins.

SM6T33A-E3/52 (Vishay General Semiconductor - Diodes Division): Active product with ROHS3 compliance and extended operating temperature range to -65°C. Clamping voltage of 45.7V closely matches the original specification. Peak pulse current of 13.1A aligns with the original design. Suitable for temperature-critical applications.

SM6T33AY (STMicroelectronics): Active product with ROHS3 compliance and automotive-grade qualification (AEC-Q101). Clamping voltage of 59V and peak pulse current of 68A (8/20µs) provide enhanced protection. Recommended for automotive and mission-critical applications requiring automotive-grade reliability.

SMBJP6KE33A-TP (Micro Commercial Co): Active product with ROHS3 compliance and extended operating temperature range to 175°C. Clamping voltage of 45.7V and peak pulse current of 13.3A match the original specification closely. Suitable for high-temperature applications.

Frequently Asked Questions (FAQ)

Q: Can I use SM6T33A or SM6T33AY as direct replacements for P6SMB33?

A: Yes. Both parts maintain the required 28.2V reverse standoff voltage, 600W peak pulse power, and DO-214AA (SMB) package. The higher clamping voltage (59V vs. 47.99V) and peak pulse current (68A vs. 13.3A) represent enhanced protection characteristics rather than incompatibility. Circuit validation is necessary to confirm the higher clamping voltage does not affect downstream component ratings.

Q: What is the difference between the clamping voltage specifications across substitute parts?

A: Clamping voltage determines the maximum voltage the TVS diode allows across its terminals during a transient event. The P6SMB33 specifies 47.99V maximum clamping. Substitutes range from 45.7V to 59V. Lower clamping voltages (45.7V) provide tighter voltage regulation; higher clamping voltages (59V) allow greater voltage excursion but may offer improved current handling. Selection depends on protected circuit voltage tolerance.

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

A: Yes. All substitute parts are housed in DO-214AA (SMB) surface-mount packages, ensuring mechanical and electrical compatibility with the original P6SMB33 PCB layout and reflow soldering processes.

Q: Which substitute part is recommended for automotive applications?

A: SM6T33AY is qualified to AEC-Q101 automotive standards and carries automotive-grade designation. This part is appropriate for automotive and mission-critical applications requiring documented reliability qualification.

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

A: The P6SMB33 operates from -55°C to 150°C. SM6T33A-E3/52 extends the lower limit to -65°C for cold-environment applications. SMBJP6KE33A-TP extends the upper limit to 175°C for high-temperature environments. Selection depends on the thermal operating envelope of the target application.

Q: Are all substitute parts RoHS compliant?

A: Yes. All substitute parts listed carry either RoHS or ROHS3 compliance certification, meeting environmental and hazardous substance restrictions for commercial and industrial applications.