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onsemi BC546BG
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- Part No.:
- BC546BG
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-226-3, TO-92-3 Long Body
- Datasheet:
-
BC546BG.pdf
- Description:
- TRANS NPN 65V 0.1A TO92
- Quantity:
- Payment:
- Shipping:
Inventory:7,261
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Product details
Overview
BC546BG from onsemi is an NPN silicon general-purpose amplifier transistor in TO-92 package, rated for 65 VCEO, 100 mA continuous collector current, and 625 mW power dissipation at 25°C ambient - used in low-power linear amplification, switching, and signal conditioning circuits in consumer electronics and industrial control interfaces.
For engineers reviewing the BC546BG datasheet, pinout, applications, or equivalent options, key selection criteria include DC current gain (hFE = 110–220 at IC = 10 mA), VCE(sat) ≤ 0.25 V at IC/IB = 10, fT = 150–300 MHz, and Pb-free TO-92 compliance for RoHS-constrained designs.
Technical Context
The BC546BG operates as a discrete bipolar junction transistor with fixed NPN polarity, optimized for medium-speed amplification and saturated switching. Its hFE binning (B grade) guarantees minimum DC current gain of 110 at IC = 10 mA and VCE = 5 V, while thermal resistance RJA = 200°C/W defines its ambient-limited power handling.
It features V(BR)CEO = 65 V, V(BR)CBO = 80 V, and VEBO = 6.0 V - enabling use in 24–48 V rail applications with margin against transients. Small-signal parameters include fT = 300 MHz (typ), Cobo = 1.7 pF, and NF = 2.0 dB at IC = 0.2 mA - supporting audio and low-frequency RF front-end roles.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 65 V - maximum safe collector-emitter voltage before breakdown; supports 48 V system rails with 35% headroom. |
| IC (continuous) | 100 mA - usable collector current limit for linear operation; sufficient for driving LEDs, relays, or small logic loads. |
| hFE (min/typ) | 110 / 200 at IC = 10 mA - ensures reliable base drive design with predictable current amplification across temperature. |
| VCE(sat) | ≤ 0.25 V at IC = 10 mA, IB = 0.5 mA - enables low-loss switching in digital interface and level-shifting circuits. |
| fT | 300 MHz (typ) - supports stable amplification up to ~50 MHz with adequate gain margin; suitable for audio and sub-MHz signal paths. |
| RJA | 200°C/W - defines thermal derating slope; requires heatsinking or airflow above ~300 mW in still air. |
Pinout & Package
BC546BG uses the standard TO-92 (Case 29, Style 17) plastic package with bent leads, 4.45–5.20 mm height, and 2.04–2.66 mm lead spacing. The device is Pb-free and RoHS-compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Collector) | Main output current terminal | Connected to load or supply rail; carries full collector current; must be isolated from base/emitter bias networks. |
| 2 (Base) | Control input terminal | Receives forward-biased current to enable conduction; requires series resistor to limit IB per hFE target. |
| 3 (Emitter) | Reference and return path | Typically grounded or tied to negative rail; establishes emitter-base voltage reference for biasing. |
Key Features
| Feature | Design Value |
|---|---|
| Pb-free TO-92 package | Fully compliant with RoHS Directive 2011/65/EU; eliminates lead contamination risk in assembly and end-of-life processing. |
| 65 V VCEO rating | Enables direct interface with 24 V and 48 V industrial control buses without external clamping components. |
| hFE = 110–220 (B grade) | Provides consistent current amplification across production lots, reducing need for individual gain binning in production test. |
| VCE(sat) ≤ 0.25 V | Minimizes power loss during saturation, critical for battery-powered switch-mode drivers and logic-level translators. |
| fT = 300 MHz (typ) | Ensures stable small-signal gain at audio frequencies with margin for harmonic content and layout parasitics. |
Applications
| Audio Pre-amplifier Stage | Microcontroller GPIO Driver |
|---|---|
|
Use Scenario: Amplifying weak microphone or sensor signals in portable audio recorders and voice-enabled IoT nodes. IC Role / Device Role / Timing Role: Discrete NPN amplifier configured in common-emitter topology with DC-coupled bias network. Use Value: Low noise figure (2.0 dB) and high hFE ensure >40 dB voltage gain with minimal added distortion at 1–10 kHz. |
Use Scenario: Driving 5 V relay coils, LED indicators, or optocoupler inputs from 3.3 V microcontroller GPIO pins. IC Role / Device Role / Timing Role: Saturated switch with base resistor selected for IB/IC ≥ 10 to guarantee hard saturation. Use Value: VCE(sat) ≤ 0.25 V limits power dissipation to <10 mW at 10 mA load, avoiding GPIO overcurrent stress. |
| Industrial Sensor Interface | Legacy Logic Level Shifter |
|
Use Scenario: Converting 0–10 V analog sensor outputs to 0–3.3 V MCU-compatible levels using emitter-follower configuration. IC Role / Device Role / Timing Role: Unity-gain buffer with high input impedance and low output impedance. Use Value: hFE ≥ 110 ensures <1% loading error on 10 kΩ source impedances; VEBO = 6.0 V prevents reverse breakdown. |
Use Scenario: Translating 5 V TTL logic outputs to 3.3 V CMOS inputs in mixed-voltage embedded systems. IC Role / Device Role / Timing Role: Active-low open-collector translator with pull-up to 3.3 V rail. Use Value: Fast turn-off (limited by Cobo = 1.7 pF) supports >1 MHz data rates; V(BR)CEO = 65 V tolerates 5 V overshoots. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN general-purpose transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BC547BG | VCEO = 45 V (vs. 65 V); otherwise identical hFE, package, and pinout. | Not suitable for 48 V bus interfaces; acceptable for 5–24 V logic and sensor circuits. | Select BC547BG only when system voltage stays below 36 V and higher VCEO margin is unnecessary. |
| MMBT3904LT1G | SOT-23 package (vs. TO-92); same VCEO = 40 V, but hFE min = 100 and fT = 300 MHz. | Requires PCB redesign for surface-mount layout; better for space-constrained, high-density boards. | Choose MMBT3904LT1G when board area is constrained and reflow compatibility is required over through-hole assembly. |
Compared with BC547BG and MMBT3904LT1G, the BC546BG offers superior voltage margin (65 V) in through-hole form factor - making it optimal for industrial 24/48 V control modules where mechanical robustness and serviceability outweigh miniaturization needs.
Availability
BC546BG is available at Aetrix Electronics and suitable for industrial sensor interfaces, audio pre-amplifiers, microcontroller GPIO drivers, and legacy logic level shifters requiring stable component supply and long-term obsolescence management.
Supply support for BC546BG includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and IoT markets.
The BC546BG belongs to onsemi's legacy general-purpose transistor family designed for cost-sensitive, high-reliability linear and switching applications in industrial controls, consumer audio, and embedded interface circuits.
FAQ
What is the maximum collector-emitter voltage rating for BC546BG?
The BC546BG has a guaranteed minimum collector-emitter breakdown voltage (V(BR)CEO) of 65 V at IC = 1.0 mA and IB = 0. This rating allows safe operation in 48 V nominal systems with transient margin. Derating is required above 25°C ambient per the 5.0 mW/°C thermal derating curve in the datasheet. Always verify actual circuit stress under worst-case conditions before finalizing BC546BG usage.
Is BC546BG pin-compatible with BC547BG or BC548BG?
Yes, BC546BG, BC547BG, and BC548BG share identical TO-92 package dimensions, pinout (Collector-Base-Emitter, Pin 1–2–3), and marking orientation. However, they differ in absolute maximum ratings: BC546BG supports 65 V VCEO, BC547BG 45 V, and BC548BG 30 V. Substitution is electrically valid only if the lower-voltage variants meet all circuit voltage requirements - BC546BG cannot be replaced by BC548BG in 48 V applications.
What is the typical DC current gain (hFE) of BC546BG at 10 mA collector current?
The BC546BG B-grade transistor has a minimum hFE of 110 and a typical value of 200 at IC = 10 mA and VCE = 5.0 V. This range is confirmed in the "ON CHARACTERISTICS" table of the official onsemi datasheet (Rev. 8, August 2021). Designers should use the minimum value for worst-case base drive calculations and verify gain stability across temperature in BC546BG-based amplifier stages.
Does BC546BG have Pb-free construction?
Yes, BC546BG is explicitly marked as Pb-free in the onsemi datasheet ordering information table and carries the "G" suffix per onsemi's packaging nomenclature. It complies with RoHS Directive 2011/65/EU and contains no lead in solderable terminations or mold compound. The device is suitable for environmentally regulated production environments where lead-free assembly is mandatory.
What is the thermal resistance junction-to-ambient (RJA) for BC546BG in free-air conditions?
The BC546BG has a specified thermal resistance RJA of 200°C/W under standard TO-92 mounting conditions (no heatsink, natural convection). This means a 625 mW power dissipation at 25°C ambient results in a junction temperature rise of 125°C - reaching the maximum rated TJ of +150°C. For sustained operation above 300 mW, forced airflow or PCB copper thermal relief is recommended to maintain BC546BG reliability.
BC546BG Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-226-3, TO-92-3 Long Body
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Transistor Type:
- NPN
- Current - Collector (Ic) (Max):
- 100 mA
- Voltage - Collector Emitter Breakdown (Max):
- 65 V
- Vce Saturation (Max) @ Ib, Ic:
- 600mV @ 5mA, 100mA
- Current - Collector Cutoff (Max):
- 15nA
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 200 @ 2mA, 5V
- Power - Max:
- 625 mW
- Frequency - Transition:
- 300MHz
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92 (TO-226)
BC546BG FAQ
1.How can I place an order for BC546BG through Aetrix?
Please submit a Request for Quotation (RFQ) for BC546BG on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for BC546BG reliable?
The price and inventory of BC546BG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC546BG is usually 5 days.
3.What payment methods are accepted for BC546BG?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC546BG transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC546BG?
BC546BG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC546BG order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for BC546BG?
For technical support, including BC546BG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC546BG requirements.
6.How does Aetrix verify that BC546BG is sourced from the original manufacturer or authorized distributors?
All BC546BG products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that BC546BG meets industry standards.
7.What is the process for return or replacement of BC546BG?
All BC546BG units undergo pre-shipment inspection (PSI). If there is an issue with BC546BG, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The BC546BG part is unused and in its original packaging.
Return procedure for BC546BG:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BC546BG Tags
-
MMBT3906LT1G
onsemi
-
MMBT3904-7-F
Diodes Incorporated
-
MMBT3904LT1G
onsemi
-
MMBT3906-7-F
Diodes Incorporated
-
MMBT3904-TP
Micro Commercial Co
-
MMBT2222A-7-F
Diodes Incorporated
-
BC846BLT1G
onsemi
-
BC847B,215
Nexperia USA Inc.
-
SMMBT3904LT1G
onsemi
-
MMBT2222A-TP
Micro Commercial Co
-
MMBTA06LT1G
onsemi
-
MMBT2222ALT1G
onsemi
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