BC858BW-HF Equivalent & Substitute Parts

Part Overview

The BC858BW-HF is an active PNP bipolar junction transistor manufactured by Comchip Technology, designed for surface mount applications in the SOT-323 package. This component operates at 30 V collector-emitter breakdown voltage with a maximum collector current of 100 mA and 150 mW power dissipation. The part is suitable for general-purpose switching and amplification circuits requiring compact form factors. Identification of equivalent and substitute parts is necessary to address supply chain variations, manufacturer availability, and design flexibility while maintaining electrical and mechanical compatibility.

Substiute Parts

BC858BW-HF

Comchip TechnologyIn Stock: 957BC858BW-HF Datasheet

Current PartRFQ

BC858BWT1G

onsemiIn Stock: 39388BC858BWT1G Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the BC858BW-HF is determined by strict equivalence across the following critical parameters:

Electrical Parameters (Must Match):

• Transistor Type: PNP
• Current - Collector (Ic) Max: 100 mA
• Voltage - Collector Emitter Breakdown (Max): 30 V
• Vce Saturation (Max): 650 mV @ 5mA, 100mA
• Current - Collector Cutoff (Max): 15 nA
• DC Current Gain (hFE) Min: 220 @ 2mA, 5V
• Power - Max: 150 mW
• Frequency - Transition: 100 MHz

Mechanical Parameters (Must Match):

• Package / Case: SC-70, SOT-323
• Mounting Type: Surface Mount

Compliance Parameters:

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

The BC858BWT1G manufactured by onsemi meets all electrical and mechanical requirements for direct substitution. Both parts share identical base product number BC858 and operate within the same parameter envelope.

Parameter Comparison

Engineering Selection Recommendations

The BC858BWT1G manufactured by onsemi is a direct parametric equivalent to the BC858BW-HF. Both components are active products with ROHS3 compliance and MSL Level 1 rating, indicating unlimited shelf life under standard storage conditions.

Selection between these parts should be based on:

Availability: The BC858BWT1G has significantly higher inventory (39,300 pcs) compared to the BC858BW-HF (869 pcs), making it the preferred choice for high-volume production or extended lead time mitigation.

Manufacturer Preference: Both manufacturers produce parts meeting identical electrical specifications. Component selection may be driven by existing supply chain relationships, qualification requirements, or procurement policies.

Operating Temperature Range: The BC858BWT1G specifies an extended operating temperature range of -55°C to 150°C, compared to the BC858BW-HF specification of 150°C maximum. This provides additional thermal margin for applications requiring low-temperature operation.

Compliance Status: Both parts maintain ROHS3 compliance and carry identical moisture sensitivity ratings, ensuring compatibility with standard PCB assembly processes and storage protocols.

Frequently Asked Questions (FAQ)

Q: Can BC858BWT1G replace BC858BW-HF in existing designs?

A: Yes. The BC858BWT1G is a direct parametric equivalent meeting all electrical and mechanical specifications of the BC858BW-HF. No circuit modifications are required for substitution.

Q: Are there package differences between these parts?

A: No. Both parts use the SC-70 / SOT-323 surface mount package with identical pinout and footprint. PCB layout and assembly processes remain unchanged.

Q: What is the significance of the extended temperature range in BC858BWT1G?

A: The BC858BWT1G operates from -55°C to 150°C, while the BC858BW-HF is specified to 150°C maximum. The extended lower temperature limit provides additional operational margin for applications in cold environments or thermal cycling scenarios.

Q: Do both parts have the same RoHS compliance status?

A: Yes. Both BC858BW-HF and BC858BWT1G are ROHS3 compliant with MSL Level 1 rating, indicating unlimited moisture sensitivity and compatibility with standard lead-free assembly processes.

Q: Which part should be selected for new designs?

A: Selection should be based on supply chain strategy and availability. The BC858BWT1G offers higher inventory levels and extended temperature range, making it suitable for designs requiring supply chain resilience or low-temperature operation.

Q: Are there any electrical performance differences between these transistors?

A: No. Both parts share identical electrical parameters including collector current, breakdown voltage, saturation voltage, current gain, power dissipation, and transition frequency.