BC547B A1G Equivalent & Substitute Parts

Part Overview

The BC547B A1G is an NPN bipolar junction transistor manufactured by Taiwan Semiconductor Corporation, designed for small-signal switching and amplification applications. This device operates at a maximum collector voltage of 45 V with a collector current rating of 100 mA and power dissipation of 500 mW in a Through Hole TO-92 package. The BC547B A1G is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement continuity. Substitute parts listed below maintain electrical and mechanical compatibility while offering active product status from alternative manufacturers.

Key Parameters

Parameter	Value	Unit
Transistor Type	NPN	—
Maximum Collector Current (Ic)	100	mA
Maximum Collector-Emitter Breakdown Voltage (Vceo)	45	V
Maximum Power Dissipation	500	mW
DC Current Gain (hFE) @ Ic=2mA, Vce=5V	200	—
Maximum Collector Cutoff Current (ICBO)	15	nA
Operating Temperature Range	−65 to 150	°C
Mounting Type	Through Hole	—
Package Type	TO-92-3 (TO-226AA)	—

Substitute Part Grouping Explanation

Substitute parts for the BC547B A1G are selected based on strict electrical and mechanical parameter matching. All substitute devices maintain the following critical specifications:

Electrical Compatibility Criteria:

Transistor type: NPN configuration
Maximum collector current: 100 mA
Maximum collector-emitter breakdown voltage: 45 V
Maximum collector cutoff current: 15 nA
DC current gain (hFE) minimum: 200 @ 2 mA, 5 V
Power dissipation: 500 mW or greater

Mechanical Compatibility Criteria:

Mounting type: Through Hole
Package type: TO-92-3 (TO-226AA) with formed leads
Pin configuration: Three-terminal device

All substitute parts listed are manufactured by Fairchild Semiconductor or onsemi and are classified as Active products with current availability. These devices are RoHS3 compliant and REACH unaffected, ensuring regulatory alignment with the original part.

Parameter Comparison

Part Number	Manufacturer	Product Status	Ic (Max) mA	Vceo (Max) V	hFE (Min) @ 2mA, 5V	Power (Max) mW	Frequency (Transition) MHz	Operating Temp (Max) °C	Package
BC547B A1G	Taiwan Semiconductor Corporation	Obsolete	100	45	200	500	—	150	TO-92-3
BC547ATA	Fairchild Semiconductor	Active	100	45	110	500	300	150	TO-92-3
BC547BTA	Fairchild Semiconductor	Active	100	45	200	625	300	150	TO-92-3
BC547BTF	onsemi	Active	100	45	200	500	300	150	TO-92-3
BC547CTA	onsemi	Active	100	45	420	500	300	150	TO-92-3
BC547CTFR	onsemi	Active	100	45	420	500	300	150	TO-92-3
BC550CTA	onsemi	Active	100	45	420	500	300	150	TO-92-3

Engineering Selection Recommendations

BC547BTA (Fairchild Semiconductor): This substitute provides direct electrical equivalence to the BC547B A1G with matching DC current gain (hFE = 200 @ 2 mA, 5 V) and identical maximum collector current and breakdown voltage specifications. The BC547BTA offers enhanced power dissipation capability (625 mW versus 500 mW) and extended operating temperature range (−55°C to 150°C). Active product status ensures long-term availability and supply chain continuity.

BC547BTF (onsemi): This substitute maintains exact electrical specifications matching the BC547B A1G, including DC current gain, collector current, and breakdown voltage. The BC547BTF is supplied in Cut Tape packaging and carries Active product status with substantial inventory availability (22,801 units). RoHS3 compliance and REACH unaffected status align with regulatory requirements.

BC547CTA and BC547CTFR (onsemi): These substitutes provide higher DC current gain (hFE = 420 @ 2 mA, 5 V) while maintaining all other critical electrical parameters. Both devices are Active products with robust inventory levels. The BC547CTFR variant is supplied in Cut Tape format with reel packaging.

BC550CTA (onsemi): This substitute belongs to the BC550 series and provides equivalent electrical performance to the BC547B A1G with higher DC current gain (hFE = 420 @ 2 mA, 5 V). Active product status and substantial inventory (13,720 units) support procurement requirements.

BC547ATA (Fairchild Semiconductor): This substitute meets all mechanical and voltage specifications but features lower DC current gain (hFE = 110 @ 2 mA, 5 V). Selection of this part requires circuit analysis to confirm gain requirements are satisfied at the reduced hFE specification.

Frequently Asked Questions (FAQ)

Q: Can BC547BTA replace BC547B A1G in all applications?

A: Yes. The BC547BTA maintains identical maximum collector current (100 mA), collector-emitter breakdown voltage (45 V), and DC current gain (200 @ 2 mA, 5 V) specifications. The BC547BTA offers additional power dissipation margin (625 mW versus 500 mW) and extended operating temperature range, making it suitable for direct substitution in existing designs.

Q: What is the difference between BC547BTF and BC547BTA?

A: Both devices provide identical electrical specifications. The primary difference is packaging format: BC547BTF is supplied in Cut Tape (CT) format, while BC547BTA is supplied in Bulk packaging. Selection depends on procurement and assembly requirements.

Q: Why do BC547CTA and BC547CTFR have higher DC current gain than the original BC547B A1G?

A: BC547CTA and BC547CTFR are graded variants within the BC547 family with higher DC current gain (420 @ 2 mA, 5 V). These devices maintain all other electrical parameters and are fully compatible substitutes. Higher gain may reduce base current requirements in amplifier circuits but does not prevent substitution in switching applications.

Q: Is BC550CTA equivalent to BC547B A1G?

A: BC550CTA provides equivalent electrical performance with identical maximum collector current, breakdown voltage, and power dissipation. The BC550CTA features higher DC current gain (420 @ 2 mA, 5 V). The BC550 series represents an alternative product line with compatible specifications suitable for direct substitution.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All substitute parts listed (BC547ATA, BC547BTA, BC547BTF, BC547CTA, BC547CTFR, and BC550CTA) are RoHS3 compliant and REACH unaffected, ensuring regulatory alignment with environmental and hazardous substance restrictions.

Q: What is the significance of the TO-92-3 package specification?

A: The TO-92-3 package (also designated TO-226AA) is a three-terminal Through Hole package with formed leads. All substitute parts use this identical package type, ensuring mechanical compatibility with existing printed circuit board layouts and assembly processes. No board redesign is required for substitution.

Q: Can BC547ATA be used as a direct replacement despite lower DC current gain?

A: BC547ATA can be substituted if circuit design analysis confirms that the lower DC current gain (110 @ 2 mA, 5 V) does not compromise circuit performance. In amplifier applications requiring specific gain characteristics, the reduced hFE may necessitate circuit parameter adjustment. In switching applications with adequate base drive, BC547ATA functions as a direct replacement.

Q: What inventory considerations apply to substitute part selection?

A: All substitute parts maintain Active product status with current inventory availability. BC547CTA offers the highest inventory level (46,986 units), followed by BC547BTF (22,801 units) and BC550CTA (13,720 units). Procurement decisions may consider inventory depth for supply chain security and lead time optimization.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message