BCW70LT1 PNP Bipolar Junction Transistor Equivalent & Substitute Parts

Part Overview

The BCW70LT1 is a PNP bipolar junction transistor manufactured by onsemi, designed for surface mount applications in the SOT-23-3 package. This device operates at a maximum collector current of 100 mA with a collector-emitter breakdown voltage of 45 V and maximum power dissipation of 225 mW. The BCW70LT1 is classified as obsolete, necessitating identification of active equivalent and substitute components for new designs and ongoing production requirements. Substitute parts must maintain electrical compatibility within the specified parameter ranges while offering active product status and current availability.

Key Parameters

Parameter	BCW70LT1 Value	Unit
Transistor Type	PNP	—
Current - Collector (Ic) Max	100	mA
Voltage - Collector Emitter Breakdown (Max)	45	V
Vce Saturation (Max)	300	mV @ 500µA, 10mA
Current - Collector Cutoff (Max)	100	nA
DC Current Gain (hFE) Min	215	@ 2mA, 5V
Power - Max	225	mW
Operating Temperature	-55 to 150	°C
Mounting Type	Surface Mount	—
Package / Case	TO-236-3, SC-59, SOT-23-3	—

Substitute Part Grouping Explanation

Substitute parts for the BCW70LT1 are classified into two categories based on electrical parameter compatibility:

Direct Equivalent (Identical Electrical Specifications): Parts that maintain all critical electrical parameters within the same ranges as the BCW70LT1, including collector current (100 mA), collector-emitter breakdown voltage (45 V), and power dissipation (225 mW). These parts are pin-compatible and functionally interchangeable without circuit modification.

Compatible Substitutes (Enhanced or Equivalent Parameters): Parts that exceed or match the BCW70LT1 specifications in key parameters such as collector current, breakdown voltage, or power dissipation. These substitutes operate within the same voltage and current envelope, maintaining compatibility with existing circuit designs while offering improved performance margins or enhanced reliability features such as automotive qualification or higher transition frequency.

Critical Parameters for Substitution:

Transistor Type: PNP (mandatory)
Collector Current (Ic Max): ≥ 100 mA
Collector-Emitter Breakdown Voltage: ≥ 45 V
Package Type: SOT-23-3 / TO-236-3 / SC-59 (pin-compatible)
Mounting Type: Surface Mount
Operating Temperature Range: Must encompass -55°C to 150°C or be compatible with application requirements

Parameter Comparison

Part Number	Manufacturer	Ic Max (mA)	Vce Breakdown (V)	Vce Sat (mV)	hFE Min	Power Max (mW)	Freq Trans (MHz)	Temp Range (°C)	Product Status	RoHS Compliance
BCW70LT1	onsemi	100	45	300 @ 500µA, 10mA	215 @ 2mA, 5V	225	—	-55 to 150	Obsolete	Non-compliant
BCW70LT1G	onsemi	100	45	300 @ 500µA, 10mA	215 @ 2mA, 5V	225	—	-55 to 150	Active	ROHS3 Compliant
2PB709BRL,215	NXP Semiconductors	200	50	250 @ 10mA, 100mA	210 @ 2mA, 10V	250	200	-55 to 150	Active	REACH Unaffected
2PB709BSL,215	NXP Semiconductors	200	50	250 @ 10mA, 100mA	210 @ 2mA, 10V	250	200	-55 to 150	Active	REACH Unaffected
2SA1037AKT146Q	Rohm Semiconductor	150	50	500 @ 5mA, 50mA	120 @ 1mA, 6V	200	140	-55 to 150	Active	ROHS3 Compliant
2SA1037AKT146R	Rohm Semiconductor	150	50	500 @ 5mA, 50mA	180 @ 1mA, 6V	200	140	-55 to 150	Active	ROHS3 Compliant
2SA1162-O,LF	Toshiba Semiconductor and Storage	150	50	300 @ 10mA, 100mA	200 @ 2mA, 6V	150	80	-55 to 125	Active	ROHS3 Compliant
BC807-16-7-F	Diodes Incorporated	500	45	700 @ 50mA, 500mA	100 @ 100mA, 1V	310	100	-55 to 150	Active	ROHS3 Compliant
BC807-40-7-F	Diodes Incorporated	500	45	700 @ 50mA, 500mA	250 @ 100mA, 1V	310	100	-55 to 150	Active	ROHS3 Compliant
BC857B-7-F	Diodes Incorporated	100	45	650 @ 5mA, 100mA	220 @ 2mA, 5V	300	200	-65 to 150	Active	ROHS3 Compliant
BC857C-7-F	Diodes Incorporated	100	45	650 @ 5mA, 100mA	420 @ 2mA, 5V	300	200	-65 to 150	Active	ROHS3 Compliant

Engineering Selection Recommendations

Primary Recommendation: BCW70LT1G

The BCW70LT1G is the direct equivalent replacement for the obsolete BCW70LT1. This part maintains identical electrical specifications across all critical parameters: 100 mA collector current, 45 V collector-emitter breakdown voltage, 225 mW power dissipation, and -55°C to 150°C operating temperature range. The BCW70LT1G carries active product status and ROHS3 compliance, addressing regulatory requirements for new designs. Packaging is identical (SOT-23-3), enabling direct substitution without circuit modification or PCB redesign.

Secondary Recommendations for Enhanced Performance:

BC857B-7-F and BC857C-7-F (Diodes Incorporated): These parts match the BCW70LT1 in collector current (100 mA) and collector-emitter breakdown voltage (45 V). Both offer enhanced power dissipation (300 mW versus 225 mW) and transition frequency (200 MHz). The BC857C-7-F provides higher DC current gain (420 @ 2mA, 5V) compared to the BCW70LT1 (215 @ 2mA, 5V), suitable for applications requiring improved switching speed or reduced base drive requirements. Operating temperature range extends to -65°C, providing wider environmental coverage. ROHS3 compliance and active product status are confirmed.

2PB709BRL,215 and 2PB709BSL,215 (NXP Semiconductors): These NXP parts exceed BCW70LT1 specifications with 200 mA collector current and 50 V breakdown voltage, providing 2× current margin and enhanced voltage headroom. Transition frequency of 200 MHz supports higher-speed switching applications. Both parts carry automotive qualification (AEC-Q101) and active product status. Selection between BRL and BSL variants depends on packaging requirements (Bulk versus Bulk).

2SA1037AKT146R and 2SA1037AKT146Q (Rohm Semiconductor): These Rohm parts provide 150 mA collector current and 50 V breakdown voltage with 140 MHz transition frequency. The 2SA1037AKT146R offers higher DC current gain (180 @ 1mA, 6V) than the Q variant (120 @ 1mA, 6V). Both carry ROHS3 compliance and active product status. Power dissipation is 200 mW, slightly below the BCW70LT1, requiring verification for high-power applications.

2SA1162-O,LF (Toshiba Semiconductor and Storage): This Toshiba part provides 150 mA collector current and 50 V breakdown voltage with 80 MHz transition frequency. Operating temperature maximum is 125°C, which is 25°C below the BCW70LT1 specification. This part is suitable for applications with reduced temperature requirements. ROHS3 compliance and active product status are confirmed.

BC807-16-7-F and BC807-40-7-F (Diodes Incorporated): These parts are suitable for applications requiring higher collector current (500 mA) while maintaining 45 V breakdown voltage. The BC807-40-7-F offers higher DC current gain (250 @ 100mA, 1V) than BC807-16-7-F (100 @ 100mA, 1V). Both provide 310 mW power dissipation and 100 MHz transition frequency. These parts are recommended only when increased current capacity is required, as they exceed the BCW70LT1 current specification.

Frequently Asked Questions (FAQ)

Q: Can BCW70LT1G be used as a direct replacement for BCW70LT1?

A: Yes. The BCW70LT1G is electrically and mechanically identical to the BCW70LT1, with the primary difference being active product status and ROHS3 compliance. Both parts share identical electrical specifications (100 mA Ic, 45 V Vce breakdown, 225 mW power, -55°C to 150°C operating range) and SOT-23-3 packaging. No circuit modification or PCB redesign is required.

Q: What is the primary reason for substituting the BCW70LT1?

A: The BCW70LT1 is classified as obsolete. The BCW70LT1G provides an active equivalent with identical specifications and improved regulatory compliance (ROHS3). For new designs or production requiring long-term component availability, BCW70LT1G is the recommended direct replacement.

Q: Are BC857B-7-F and BC857C-7-F interchangeable with BCW70LT1?

A: Both BC857B-7-F and BC857C-7-F are pin-compatible substitutes with identical collector current (100 mA) and breakdown voltage (45 V) specifications. The primary differences are enhanced power dissipation (300 mW versus 225 mW), higher transition frequency (200 MHz), and extended temperature range (-65°C to 150°C). The BC857C-7-F offers significantly higher DC current gain (420 versus 215), which may affect circuit biasing. Verification of base drive requirements is recommended when selecting the BC857C-7-F variant.

Q: Can NXP 2PB709 parts replace BCW70LT1 in all applications?

A: The 2PB709BRL,215 and 2PB709BSL,215 are compatible substitutes with enhanced specifications: 200 mA collector current (versus 100 mA), 50 V breakdown voltage (versus 45 V), and 250 mW power dissipation (versus 225 mW). These parts provide performance margin and automotive qualification (AEC-Q101). However, the higher Vce saturation (250 mV @ 10mA, 100mA versus 300 mV @ 500µA, 10mA) and different hFE test conditions require circuit verification for applications with tight saturation voltage requirements.

Q: What is the difference between 2SA1037AKT146R and 2SA1037AKT146Q?

A: Both parts share identical electrical specifications except for DC current gain: 2SA1037AKT146R provides 180 @ 1mA, 6V, while 2SA1037AKT146Q provides 120 @ 1mA, 6V. The higher gain of the R variant may reduce base drive requirements in switching applications. Both parts offer 150 mA collector current, 50 V breakdown voltage, and 140 MHz transition frequency. Selection depends on circuit biasing requirements and gain tolerance specifications.

Q: Is 2SA1162-O,LF suitable for all BCW70LT1 applications?

A: The 2SA1162-O,LF is a compatible substitute with 150 mA collector current and 50 V breakdown voltage. However, the maximum operating temperature is 125°C, which is 25°C below the BCW70LT1 specification of 150°C. This part is suitable only for applications with maximum junction temperatures not exceeding 125°C. Thermal analysis is required to confirm compatibility.

Q: When should BC807-16-7-F or BC807-40-7-F be selected?

A: The BC807 series parts (500 mA collector current) should be selected only when the application requires higher current capacity than the BCW70LT1 (100 mA). These parts maintain 45 V breakdown voltage and SOT-23-3 packaging. The BC807-40-7-F offers higher DC current gain (250 @ 100mA, 1V) compared to BC807-16-7-F (100 @ 100mA, 1V). For applications operating at or below 100 mA, BC857B-7-F or BC857C-7-F are preferred due to better gain matching with the original BCW70LT1.

Q: Are all substitute parts ROHS3 compliant?

A: All substitute parts listed carry either ROHS3 compliance or REACH Unaffected status. The original BCW70LT1 is RoHS non-compliant. For new designs subject to RoHS regulations, BCW70LT1G, BC857B-7-F, BC857C-7-F, 2SA1037AKT146R, 2SA1037AKT146Q, and 2SA1162-O,LF all meet ROHS3 requirements. The NXP 2PB709 variants carry REACH Unaffected status, which is acceptable for most applications.

Q: What packaging options are available for substitute parts?

A: All substitute parts are available in SOT-23-3 (TO-236-3, SC-59) surface mount packaging, maintaining pin compatibility with the BCW70LT1. Packaging variants differ in tape format: BCW70LT1G is supplied in Tape & Reel (TR), while BC857B-7-F and BC857C-7-F are available in Tape & Reel (TR). The 2SA1037 variants are supplied in Cut Tape (CT) & Digi-Reel®. Packaging selection depends on production volume and assembly equipment compatibility.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message