MMBT3906-TP-HF Equivalent & Substitute Parts

Part Overview

The MMBT3906-TP-HF is a PNP bipolar junction transistor manufactured by Micro Commercial Co, designed for general-purpose switching and amplification applications. This surface mount device operates at a maximum collector current of 200 mA with a 40 V collector-emitter breakdown voltage and 250 MHz transition frequency. The component is housed in a SOT-23 package and dissipates up to 300 mW.

The MMBT3906-TP-HF maintains Active product status with 771 pieces currently in stock. Equivalent and substitute parts are identified to support design flexibility, inventory management, and supply chain continuity when the primary part becomes unavailable or when alternative packaging or manufacturer options are required.

Substiute Parts

MMBT3906-TP-HF

Micro Commercial CoIn Stock: 843MMBT3906-TP-HF Datasheet

Current PartRFQ

BC858B-7-F

Diodes IncorporatedIn Stock: 1956BC858B-7-F Datasheet

SimilarRFQ

MMBT3906LT1HTSA1

Infineon TechnologiesIn Stock: 39946MMBT3906LT1HTSA1 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the MMBT3906-TP-HF is determined by electrical and mechanical compatibility across the following critical parameters:

Electrical Compatibility Criteria:

• Transistor type must be PNP
• Collector current rating must equal or exceed 200 mA
• Collector-emitter breakdown voltage must equal or exceed 40 V
• Transition frequency must equal or exceed 250 MHz
• Power dissipation must equal or exceed 300 mW
• DC current gain (hFE) characteristics must support the intended application bias point

Mechanical Compatibility Criteria:

• Package type must be SOT-23 or equivalent (TO-236-3, SC-59, SOT-23-3)
• Surface mount mounting type required
• Pin configuration must match SOT-23 standard

Substitute Parts Identified:

1. MMBT3906LT1HTSA1 (Infineon Technologies) — Direct electrical equivalent with identical maximum ratings and performance characteristics. Differs in product status (Last Time Buy) and packaging format (Cut Tape vs. Tape & Reel).

2. BC858B-7-F (Diodes Incorporated) — Partial substitute with reduced maximum ratings. Collector current limited to 100 mA (50% of primary part) and collector-emitter breakdown voltage limited to 30 V (75% of primary part). Transition frequency reduced to 200 MHz. Suitable only for applications with lower current and voltage requirements.

Parameter Comparison

Engineering Selection Recommendations

MMBT3906LT1HTSA1 (Infineon Technologies) is the primary direct substitute for the MMBT3906-TP-HF. This part maintains identical electrical specifications including 200 mA maximum collector current, 40 V breakdown voltage, 250 MHz transition frequency, and matching DC current gain characteristics. The part is packaged in PG-SOT23 format with Cut Tape (CT) packaging. ROHS3 compliance and unlimited moisture sensitivity level (MSL 1) are confirmed. The part carries Last Time Buy status, indicating limited future availability; procurement should account for this designation.

BC858B-7-F (Diodes Incorporated) functions as a partial substitute only for applications with reduced electrical requirements. The 100 mA maximum collector current represents a 50% reduction from the primary part specification. The 30 V collector-emitter breakdown voltage is insufficient for circuits requiring the full 40 V rating of the MMBT3906-TP-HF. The 200 MHz transition frequency is lower than the primary part. This substitute is suitable only when circuit design margins accommodate these reduced ratings. The part maintains Active product status and ROHS3 compliance.

Selection between substitutes depends on application requirements and supply chain constraints. Direct electrical equivalence favors MMBT3906LT1HTSA1 despite Last Time Buy status. Reduced-rating applications may utilize BC858B-7-F with design verification.

Frequently Asked Questions (FAQ)

Q: Can MMBT3906LT1HTSA1 replace MMBT3906-TP-HF in all applications?

A: Yes, MMBT3906LT1HTSA1 provides direct electrical substitution with identical maximum ratings and performance characteristics. Both parts support 200 mA collector current, 40 V breakdown voltage, and 250 MHz transition frequency. The primary difference is packaging format (Cut Tape vs. Tape & Reel) and product status (Last Time Buy). Mechanical compatibility is confirmed through identical SOT-23 package specifications.

Q: Is BC858B-7-F a direct replacement for MMBT3906-TP-HF?

A: No. BC858B-7-F is a partial substitute with reduced electrical ratings. Maximum collector current is limited to 100 mA (versus 200 mA), collector-emitter breakdown voltage is 30 V (versus 40 V), and transition frequency is 200 MHz (versus 250 MHz). This part is suitable only for applications designed to operate within these lower specifications. Circuit redesign or derating analysis is required before substitution.

Q: What are the package compatibility requirements?

A: All identified substitutes use SOT-23 surface mount packaging (also designated TO-236-3 or SC-59). Pin configuration and footprint are standardized across these parts. PCB layout and reflow soldering parameters remain compatible without modification.

Q: Why is MMBT3906LT1HTSA1 marked as Last Time Buy?

A: Last Time Buy status indicates the manufacturer (Infineon Technologies) has announced end-of-life for this part number. Existing inventory remains available, but future production is not planned. This designation does not affect electrical performance or reliability of current stock. Long-term supply planning should consider this status when selecting this substitute.

Q: What compliance certifications apply to these substitutes?

A: MMBT3906LT1HTSA1 and BC858B-7-F both carry ROHS3 compliance certification. Both parts are REACH Unaffected. ECCN classification is EAR99 for all parts. HTSUS code 8541.21.0075 applies uniformly across the product group.

Q: Are there differences in saturation voltage characteristics between substitutes?

A: Yes. MMBT3906-TP-HF and MMBT3906LT1HTSA1 specify 400 mV saturation voltage at 5 mA base current and 50 mA collector current. BC858B-7-F specifies 650 mV saturation voltage at 5 mA base current and 100 mA collector current. Higher saturation voltage in BC858B-7-F may affect switching speed and power dissipation in saturation-mode applications.

Q: What is the operating temperature range for each part?

A: MMBT3906-TP-HF and MMBT3906LT1HTSA1 operate from -55°C to 150°C (junction temperature). BC858B-7-F operates from -65°C to 150°C, providing extended low-temperature capability. All parts support the standard industrial temperature range.