BC857B-HF Equivalent & Substitute Parts Reference

Part Overview

The BC857B-HF is a PNP bipolar junction transistor manufactured by Comchip Technology, designed for general-purpose switching and amplification applications. This surface mount device operates at 45 V collector-emitter breakdown voltage with a maximum collector current of 100 mA and 250 mW power dissipation. The part is currently in active production status with 839 pieces in stock.

Substitute parts are necessary when the primary part becomes unavailable, when alternative manufacturers offer improved specifications, or when design requirements demand enhanced performance characteristics such as higher frequency response, improved saturation characteristics, or automotive-grade qualification.

Key Parameters

Parameter	Value	Unit
Transistor Type	PNP	—
Collector Current (Max)	100	mA
Collector-Emitter Breakdown Voltage (Max)	45	V
Power Dissipation (Max)	250	mW
Transition Frequency	100	MHz
Operating Temperature Range	-65 to 150	°C
Package Type	SOT-23-3 (TO-236-3)	—
Mounting Type	Surface Mount	—
RoHS Compliance	ROHS3 Compliant	—

Substitute Part Grouping Explanation

Substitution eligibility for the BC857B-HF is determined by the following mandatory parameters:

Critical Parameters (Must Match):

Transistor Type: PNP
Collector Current (Max): 100 mA
Collector-Emitter Breakdown Voltage (Max): 45 V
Package/Case: TO-236-3, SC-59, SOT-23-3
Mounting Type: Surface Mount

Allowable Variation Parameters:

Power Dissipation: 250 mW or greater
Transition Frequency: 100 MHz or greater
DC Current Gain (hFE): 125 or greater at specified conditions
Vce Saturation: 650 mV or lower at rated conditions
Operating Temperature: -65°C to 150°C or subset thereof
Collector Cutoff Current (ICBO): 10 nA to 100 nA

All substitute parts listed maintain identical critical parameters while offering equal or superior performance in allowable variation parameters. Substitutes are grouped by manufacturer and product status to facilitate procurement decisions.

Parameter Comparison

Part Number	Manufacturer	Ic (Max) mA	Vce(br) V	Power mW	fT MHz	hFE @ Ic, Vce	Vce Sat mV	Status
BC857B-HF	Comchip Technology	100	45	250	100	125 @ 2.2mA, 5V	650 @ 5mA, 100mA	Active
2PB709ART,215	NXP USA Inc.	100	45	250	70	210 @ 2mA, 10V	500 @ 10mA, 100mA	Active
BCW70,215	Nexperia USA Inc.	100	45	250	100	215 @ 2mA, 5V	150 @ 2.5mA, 50mA	Active
BC857A RFG	Taiwan Semiconductor Corporation	100	45	200	100	125 @ 2mA, 5V	650 @ 5mA, 100mA	Active
BC857ALT1G	onsemi	100	45	300	100	125 @ 2mA, 5V	650 @ 5mA, 100mA	Active
BC857B RFG	Taiwan Semiconductor Corporation	100	45	200	100	220 @ 2mA, 5V	650 @ 5mA, 100mA	Active
BC857B-7-F	Diodes Incorporated	100	45	300	200	220 @ 2mA, 5V	650 @ 5mA, 100mA	Active
BC857BE6433HTMA1	Infineon Technologies	100	45	330	250	220 @ 2mA, 5V	650 @ 5mA, 100mA	Last Time Buy
BC857C RFG	Taiwan Semiconductor Corporation	100	45	200	100	420 @ 2mA, 5V	650 @ 5mA, 100mA	Active
BC857CLT3G	onsemi	100	45	300	100	420 @ 2mA, 5V	650 @ 5mA, 100mA	Active
BC860BE6327HTSA1	Infineon Technologies	100	45	330	250	220 @ 2mA, 5V	650 @ 5mA, 100mA	Last Time Buy

Engineering Selection Recommendations

Primary Substitutes (Active Status, Highest Compatibility):

BC857ALT1G (onsemi) and BC857CLT3G (onsemi) are recommended as primary substitutes. Both parts maintain identical electrical specifications to the BC857B-HF while offering 300 mW power dissipation (20% margin above the 250 mW requirement). onsemi maintains extensive inventory (747,693 and 15,691 pieces respectively), ensuring supply continuity. Both parts are RoHS3 compliant with unlimited moisture sensitivity level (MSL 1).

BC857B-7-F (Diodes Incorporated) provides enhanced performance with 200 MHz transition frequency (double the BC857B-HF specification) and 300 mW power dissipation. This part is suitable for applications requiring higher frequency response. Inventory availability is substantial at 80,300 pieces.

Secondary Substitutes (Active Status, Specific Applications):

BCW70,215 (Nexperia USA Inc.) offers superior saturation characteristics with 150 mV Vce(sat) at 2.5 mA/50 mA, compared to 650 mV for the BC857B-HF. This part is automotive-grade (AEC-Q101 qualified) and suitable for switching applications requiring minimal saturation voltage. Inventory: 4,671 pieces.

2PB709ART,215 (NXP USA Inc.) is automotive-grade (AEC-Q101 qualified) with improved saturation performance (500 mV at 10 mA/100 mA). This part is suitable for automotive and industrial applications. Inventory: 35,300 pieces.

Transitional Substitutes (Last Time Buy Status):

BC857BE6433HTMA1 and BC860BE6327HTSA1 (both Infineon Technologies) offer the highest performance specifications with 250 MHz transition frequency and 330 mW power dissipation. However, both parts carry Last Time Buy status, indicating discontinued production. These parts are suitable only for applications where existing inventory can support long-term requirements or where design migration is planned.

Not Recommended for Direct Substitution:

BC857A RFG and BC857B RFG (Taiwan Semiconductor Corporation) offer only 200 mW power dissipation, which is below the 250 mW specification of the BC857B-HF. These parts are suitable only for applications with reduced thermal requirements.

Frequently Asked Questions (FAQ)

Q: Can BC857ALT1G directly replace BC857B-HF without circuit modification?

A: Yes. BC857ALT1G maintains all critical electrical parameters (100 mA Ic, 45 V Vce(br), PNP type, SOT-23-3 package) and offers superior power dissipation (300 mW vs. 250 mW). No circuit modification is required.

Q: What is the difference between BC857B-7-F and BC857B-HF?

A: BC857B-7-F offers doubled transition frequency (200 MHz vs. 100 MHz) and increased power dissipation (300 mW vs. 250 mW). All other critical parameters are identical. BC857B-7-F is suitable for higher-frequency applications.

Q: Are automotive-grade substitutes (BCW70,215, 2PB709ART,215) compatible with non-automotive applications?

A: Yes. Automotive-grade parts (AEC-Q101 qualified) meet or exceed commercial-grade specifications and are fully compatible with non-automotive applications. The automotive qualification indicates enhanced reliability and stricter manufacturing controls.

Q: Why do some substitutes show different Vce saturation values?

A: Vce saturation varies based on measurement conditions (base current and collector current). BCW70,215 shows 150 mV at 2.5 mA/50 mA, while BC857B-HF shows 650 mV at 5 mA/100 mA. Lower saturation voltage indicates superior switching performance in high-current applications.

Q: Can I use BC857BE6433HTMA1 or BC860BE6327HTSA1 for new designs?

A: Both parts carry Last Time Buy status, indicating discontinued production. These parts are not recommended for new designs. Use BC857ALT1G, BC857CLT3G, or BC857B-7-F instead.

Q: What is the significance of DC Current Gain (hFE) differences among substitutes?

A: hFE determines the base current required to achieve a specified collector current. Higher hFE (e.g., 420 in BC857C RFG) requires less base drive current than lower hFE (e.g., 125 in BC857B-HF). Both are functionally equivalent; hFE differences affect circuit biasing but not substitutability.

Q: Are all listed substitutes RoHS3 compliant?

A: Yes. All active-status substitute parts listed are RoHS3 compliant. Last Time Buy parts (BC857BE6433HTMA1, BC860BE6327HTSA1) are also RoHS3 compliant.

Q: What packaging options are available for BC857B-HF substitutes?

A: All substitutes use identical packaging: TO-236-3, SC-59, or SOT-23-3 (equivalent designations). All are surface mount devices suitable for automated assembly. Tape & Reel (TR) and Bulk packaging options are available depending on the specific substitute part number.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message