BC547B,112 Equivalent & Substitute Parts Reference

Part Overview

The BC547B,112 is an NPN bipolar junction transistor manufactured by NXP USA Inc., designed for small-signal amplification and switching applications. This device operates at a maximum collector voltage of 45 V with a collector current rating of 100 mA and dissipates up to 500 mW. The part is classified as obsolete, which necessitates identification of active equivalent alternatives that maintain electrical and mechanical compatibility for ongoing production and repair applications.

Key Parameters

Parameter	Value	Unit
Transistor Type	NPN	—
Voltage - Collector Emitter Breakdown (Max)	45	V
Current - Collector (Ic) (Max)	100	mA
Power - Max	500	mW
DC Current Gain (hFE) (Min) @ Ic, Vce	200 @ 2mA, 5V	—
Vce Saturation (Max) @ Ib, Ic	400	mV @ 5mA, 100mA
Current - Collector Cutoff (Max)	15	nA
Frequency - Transition	100	MHz
Operating Temperature (Max)	150	°C
Mounting Type	Through Hole	—
Package / Case	TO-92-3	—

Substitute Part Grouping Explanation

Substitution of the BC547B,112 is determined by strict equivalence across the following critical parameters:

Electrical Equivalence Criteria:

Transistor type must be NPN
Collector-emitter breakdown voltage must be ≥45 V
Maximum collector current must be ≥100 mA
Maximum power dissipation must be ≥500 mW
DC current gain (hFE) minimum must be ≥200 @ 2mA, 5V
Collector cutoff current must be ≤15 nA

Mechanical Equivalence Criteria:

Package type must be TO-92-3 (TO-226-3)
Mounting type must be Through Hole with formed leads

All substitute parts listed below meet or exceed these parameters and maintain pin-compatible TO-92-3 packaging, ensuring direct replacement capability in existing circuit designs.

Parameter Comparison

Parameter	BC547B,112 (NXP)	BC547B (Diotec)	BC547BBU (onsemi)	BC547BTA (Fairchild)
Manufacturer	NXP USA Inc.	Diotec Semiconductor	onsemi	Fairchild Semiconductor
Product Status	Obsolete	Active	Active	Active
Transistor Type	NPN	NPN	NPN	NPN
Voltage - Collector Emitter Breakdown (Max)	45 V	45 V	45 V	45 V
Current - Collector (Ic) (Max)	100 mA	100 mA	100 mA	100 mA
Power - Max	500 mW	500 mW	500 mW	625 mW
DC Current Gain (hFE) (Min) @ Ic, Vce	200 @ 2mA, 5V	200 @ 2mA, 5V	200 @ 2mA, 5V	200 @ 2mA, 5V
Vce Saturation (Max) @ Ib, Ic	400 mV @ 5mA, 100mA	600 mV @ 5mA, 100mA	600 mV @ 5mA, 100mA	600 mV @ 5mA, 100mA
Current - Collector Cutoff (Max)	15 nA	15 nA	15 nA	15 nA
Frequency - Transition	100 MHz	300 MHz	300 MHz	300 MHz
Operating Temperature (Max)	150°C	150°C	150°C	150°C
Package / Case	TO-92-3	TO-92-3	TO-92-3	TO-92-3
Mounting Type	Through Hole	Through Hole	Through Hole	Through Hole
RoHS Status	ROHS3 Compliant	Not applicable	ROHS3 Compliant	Not specified
REACH Status	REACH Unaffected	Vendor Undefined	REACH Unaffected	Not specified

Engineering Selection Recommendations

BC547B (Diotec Semiconductor): This part is electrically equivalent with active product status. It provides identical electrical specifications for all critical parameters. The transition frequency of 300 MHz exceeds the original 100 MHz specification, offering improved high-frequency performance. Diotec's device is suitable for direct replacement in applications where RoHS compliance status is not a procurement requirement.

BC547BBU (onsemi): This substitute maintains full electrical equivalence and is manufactured by onsemi with active product status. It carries ROHS3 compliance certification matching the original part. The 300 MHz transition frequency provides enhanced performance margin. This part is recommended for applications requiring RoHS3 compliance documentation and REACH compliance assurance.

BC547BTA (Fairchild Semiconductor): This Fairchild-manufactured alternative exceeds the original specification with 625 mW maximum power dissipation compared to 500 mW, providing additional thermal margin. It maintains all critical electrical parameters and active product status. The 300 MHz transition frequency offers performance enhancement. This part is suitable for applications requiring higher power dissipation capability within the same package envelope.

All three substitute parts are pin-compatible with the original BC547B,112 in TO-92-3 packaging and support direct circuit board replacement without layout modification.

Frequently Asked Questions (FAQ)

Q: Can BC547B (Diotec) directly replace BC547B,112 (NXP) in existing designs?

A: Yes. Both parts are NPN transistors with identical maximum ratings for collector voltage (45 V), collector current (100 mA), and DC current gain (200 @ 2mA, 5V). Both use TO-92-3 through-hole packaging with formed leads. The Diotec part's higher transition frequency (300 MHz vs. 100 MHz) is a performance enhancement that does not affect compatibility.

Q: What is the difference between BC547BBU and BC547BTA?

A: BC547BBU (onsemi) and BC547BTA (Fairchild) differ in maximum power dissipation: BC547BBU is rated at 500 mW while BC547BTA is rated at 625 mW. Both maintain identical electrical parameters for voltage, current, and gain. BC547BTA provides additional thermal headroom for applications operating near power limits. Both use TO-92-3 packaging.

Q: Are there compliance differences between the substitute parts?

A: BC547BBU carries ROHS3 and REACH Unaffected certifications matching the original NXP part. BC547B (Diotec) has undefined REACH status and not-applicable RoHS status. BC547BTA compliance status is not specified in available documentation. For applications requiring specific regulatory compliance, BC547BBU is the recommended choice.

Q: Does the higher transition frequency of substitute parts affect circuit operation?

A: The substitute parts' 300 MHz transition frequency exceeds the original 100 MHz specification. This represents improved high-frequency performance and does not degrade circuit operation. Applications designed for 100 MHz operation will function identically with higher-frequency devices. No circuit redesign is required.

Q: Can these parts be used interchangeably in the same circuit?

A: Yes. All substitute parts maintain electrical equivalence across collector voltage, collector current, DC current gain, and saturation voltage specifications. The TO-92-3 package ensures mechanical compatibility. Parts may be selected based on availability, compliance requirements, or thermal margin needs without circuit modification.

Q: What is the significance of Vce saturation differences?

A: The original BC547B,112 specifies 400 mV saturation voltage, while all substitutes specify 600 mV. Both values are within acceptable limits for small-signal switching applications. The higher saturation voltage of substitutes represents a minor performance difference that does not affect circuit functionality in standard amplification or switching configurations.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message