SACB45 Transient Voltage Suppressor Equivalent & Substitute Parts

Part Overview

The SACB45 is an active Transient Voltage Suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose transient protection applications. This unidirectional zener diode operates in the 45V reverse standoff voltage class with a 77V maximum clamping voltage and 6.8A peak pulse current capability in a surface-mount SMB (DO-214AA) package. The part is ROHS3 compliant and carries unlimited moisture sensitivity rating (MSL 1), making it suitable for standard manufacturing environments. Equivalent and substitute parts are identified based on matching electrical parameters and package compatibility to ensure functional interchangeability in circuit protection applications.

Substiute Parts

SACB45

Littelfuse Inc.In Stock: 2908SACB45 Datasheet

Current PartRFQ

SMBJ45A

MDDIn Stock: 46008SMBJ45A Datasheet

MFR RecommendedRFQ

SMBJ45A

MDDIn Stock: 46008SMBJ45A Datasheet

MFR RecommendedRFQ

SMBJ45A-13-F

Diodes IncorporatedIn Stock: 8608SMBJ45A-13-F Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SACB45 are qualified based on the following electrical and mechanical parameters:

• Voltage - Reverse Standoff (Typ): 45V
• Voltage - Breakdown (Min): 50V
• Unidirectional Channels: 1
• Package / Case: DO-214AA, SMB (surface mount)
• Mounting Type: Surface Mount
• Applications: General Purpose
• RoHS Status: ROHS3 Compliant
• Moisture Sensitivity Level: 1 (Unlimited)

Substitute parts must maintain the same reverse standoff voltage class, breakdown voltage threshold, and surface-mount SMB package configuration. Variations in clamping voltage, peak pulse current, and power dissipation are permitted within the constraints of the application circuit, provided the substitute part does not exceed the original part's voltage ratings and maintains compatibility with the PCB footprint and thermal requirements.

Parameter Comparison

Engineering Selection Recommendations

All three parts—SACB45 (Littelfuse Inc.), SMBJ45A (MDD), and SMBJ45A-13-F (Diodes Incorporated)—are active products with ROHS3 compliance and unlimited moisture sensitivity rating. Selection among these parts is determined by availability, lead time, and application-specific thermal or current requirements.

The SMBJ45A-13-F from Diodes Incorporated maintains the full operating temperature range of -55 to 150°C, matching the SACB45 specification. The SMBJ45A from MDD operates within -50 to 150°C, which is acceptable for most general-purpose applications but represents a 5°C reduction at the lower temperature extreme.

Both substitute parts offer improved peak pulse current (8.3A versus 6.8A) and power dissipation (600W versus 500W), providing additional margin in transient protection circuits. The clamping voltage of 72.7V is lower than the SACB45 specification of 77V, resulting in tighter voltage regulation during transient events. This characteristic is beneficial for protecting sensitive downstream components but must be evaluated against the specific circuit protection requirements.

Frequently Asked Questions (FAQ)

Q: Can SMBJ45A or SMBJ45A-13-F be used as direct replacements for SACB45?

A: Yes. Both substitute parts maintain the same 45V reverse standoff voltage, 50V minimum breakdown voltage, and DO-214AA SMB surface-mount package. The electrical parameters are compatible with general-purpose transient protection applications. Verify that the lower clamping voltage (72.7V versus 77V) and higher peak pulse current (8.3A versus 6.8A) align with your circuit design requirements.

Q: What is the difference between SMBJ45A from MDD and SMBJ45A-13-F from Diodes Incorporated?

A: Both parts share identical electrical specifications (45V standoff, 50V breakdown, 72.7V clamping, 8.3A peak pulse current, 600W power dissipation). The primary difference is the operating temperature range: SMBJ45A-13-F supports -55 to 150°C (matching SACB45), while SMBJ45A supports -50 to 150°C. For applications requiring full -55°C operation, SMBJ45A-13-F is the preferred choice.

Q: Are there any package or footprint compatibility concerns?

A: No. All three parts use the DO-214AA SMB surface-mount package with identical PCB footprints. Direct board-level substitution is possible without layout modifications.

Q: How do the clamping voltage differences affect circuit protection?

A: The SACB45 clamps at a maximum of 77V, while both substitute parts clamp at 72.7V. Lower clamping voltage provides tighter voltage regulation during transient events, which is generally beneficial for protecting sensitive components. Ensure your circuit design accommodates the lower clamping threshold.

Q: Are all parts RoHS and REACH compliant?

A: Yes. SACB45, SMBJ45A, and SMBJ45A-13-F are all ROHS3 compliant and REACH unaffected. All parts carry MSL 1 (unlimited) moisture sensitivity rating, suitable for standard manufacturing and storage conditions.