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onsemi BC237BRL1
- Part No.:
- BC237BRL1
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-226-3, TO-92-3 Long Body, Formed Leads
- Datasheet:
-
BC237BRL1.pdf
- Description:
- TRANS NPN 45V 0.1A TO92
- Quantity:
- Payment:
- Shipping:
Inventory:4,352
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Product details
Overview
BC237BRL1 from onsemi is an NPN silicon general-purpose amplifier transistor in TO-92 package, rated for VCEO = 45 V, IC = 100 mA, PD = 350 mW at TA = 25°C, with hFE = 200–380 (at IC = 10 mA, VCE = 5 V), and fT = 150 MHz - used in low-noise audio preamplifier stages and signal switching circuits.
For engineers reviewing the BC237BRL1 datasheet, pinout, applications, or equivalent options, key selection criteria include DC current gain consistency across collector current range, saturation voltage at defined IC/IB ratios, thermal resistance (RJA = 357 °C/W), and Pb-free tape-and-reel packaging compliance for automated SMT assembly.
Technical Context
The BC237BRL1 operates as a medium-speed, low-power NPN bipolar junction transistor optimized for linear amplification and switching in ambient-temperature-stable circuits. Its design emphasizes low noise figure (NF = 4.0 dB at IC = 0.2 mA, f = 1 kHz) and predictable hFE behavior over 0.2–100 mA collector current range, validated per Figure 1 and Figure 2 of the official datasheet.
It features fixed terminal assignment (Collector–Base–Emitter on pins 1–2–3), TO-92 case 29-11 mechanical form factor, and thermal performance governed by RJA = 357 °C/W and RJC = 125 °C/W - enabling use in non-heatsinked PCB layouts where power dissipation remains below 200 mW under continuous operation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 45 V - maximum safe collector-emitter voltage before breakdown; defines headroom for single-supply audio amplifier rails up to ±22 V. |
| IC (max) | 100 mA - continuous collector current limit; supports small-signal gain stages driving loads ≤1 kΩ at ≤5 V. |
| hFE | 200–380 @ IC = 10 mA - tight DC current gain spread ensures consistent biasing without individual trimming in production. |
| fT | 150 MHz - unity-gain bandwidth confirms suitability for RF preamp and IF amplifier stages up to ~30 MHz with stable gain. |
| VCE(sat) | 0.2 V @ IC = 10 mA, IB = 0.5 mA - low saturation voltage enables efficient switching in logic-level interface circuits. |
| NF | 4.0 dB @ IC = 0.2 mA - quantified noise performance validates use in microphone preamplifiers and sensor front-ends. |
Pinout & Package
BC237BRL1 uses the standard TO-92 (Case 29-11, Style 17) plastic package with 3 leads, lead spacing 2.54 mm, and body dimensions 4.45 × 5.20 × 3.18 mm (L × W × H). Pin 1 is Collector, Pin 2 is Base, Pin 3 is Emitter - verified per marking diagram and package outline drawing in BC237/D Rev. 4.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Collector) | Main output current path | Connected to load or next stage; requires voltage margin ≥VCEO and heatsinking if PD > 150 mW. |
| 2 (Base) | Current-controlled input node | Drives with 0.5–5 mA to achieve target IC; base resistor must limit IB to avoid exceeding max IC/hFE(min). |
| 3 (Emitter) | Reference terminal for bias network | Typically grounded or connected to emitter degeneration resistor; sets DC operating point and AC impedance. |
Key Features
| Feature | Design Value |
|---|---|
| Pb-free RoHS-compliant packaging | BC237BRL1G variant available; BC237BRL1 meets JEDEC J-STD-609A Class 1 moisture sensitivity and Pb-free reflow profile. |
| Controlled hFE binning (B grade) | Guaranteed 200–380 at IC = 10 mA, enabling predictable DC bias without feedback adjustment in discrete amplifier designs. |
| Low VCE(sat) and VBE(sat) | 0.2 V and 0.83 V respectively at IC/IB = 10 - reduces conduction loss and improves efficiency in switching applications. |
| Stable fT across temperature | 150 MHz minimum at TA = 25°C - supports broadband analog signal conditioning without gain peaking compensation. |
Applications
| Audio Preamp Stage | Signal Switching Interface |
|---|---|
Use Scenario: Amplifying low-level microphone or piezoelectric sensor outputs in battery-powered portable recorders. IC Role / Device Role / Timing Role: Small-signal NPN amplifier configured in common-emitter topology with emitter degeneration. Use Value: 4.0 dB noise figure and 200+ hFE ensure high SNR and stable gain without active bias compensation. |
Use Scenario: Level-shifting TTL/CMOS logic signals to drive LEDs, relays, or optocouplers in industrial control panels. IC Role / Device Role / Timing Role: Digital switch operating in saturation/cutoff modes with fast turn-on/turn-off due to low Cobo (4.5 pF). Use Value: VCE(sat) ≤ 0.2 V minimizes power loss; TO-92 footprint allows direct replacement of legacy BC547 variants. |
| RF Front-End Amplifier | Current Mirror Reference |
Use Scenario: Low-gain IF amplifier in AM/FM radio receivers operating at 10.7 MHz or 455 kHz intermediate frequencies. IC Role / Device Role / Timing Role: Common-emitter RF amplifier biased at IC = 1–5 mA for optimal fT and NF tradeoff. Use Value: 150 MHz fT and 4.5 pF Cobo support stable gain up to 30 MHz without neutralization. |
Use Scenario: Building matched current sources in analog sensor signal conditioning ICs or precision DAC output buffers. IC Role / Device Role / Timing Role: Paired BC237BRL1 transistors in emitter-coupled configuration to generate temperature-stable reference currents. Use Value: Tight hFE binning (B grade) and identical TO-92 thermal mass enable <1% current matching across 0–70°C. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN amplifier transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BC547B | Same TO-92 package; VCEO = 45 V, hFE = 200–450, fT = 300 MHz, but higher Cibo (10 pF) and no guaranteed NF spec. | Better high-frequency response but less optimized for low-noise audio; not specified for NF ≤ 4.0 dB. | Select BC547B only when bandwidth >100 MHz is required and noise is secondary; verify layout parasitics. |
| PN2222A | TO-92; VCEO = 40 V, IC = 800 mA, hFE = 100–300, RJA = 200 °C/W - higher power rating but looser hFE tolerance and no NF characterization. | Suitable for higher-current switching but lacks documented low-noise performance; thermal design differs significantly. | Choose PN2222A for loads >100 mA or when board-level heatsinking is available; avoid for sensitive analog front-ends. |
Compared with BC547B and PN2222A, BC237BRL1 offers the narrowest hFE bin and certified noise figure - making it preferred for production-grade audio preamps and precision current mirrors where parameter consistency and low-noise operation are design-critical.
Availability
BC237BRL1 is available at Aetrix Electronics and suitable for audio preamplifier stages, signal switching interfaces, RF front-end amplifiers, and current mirror references requiring stable component supply, Pb-free compliance, and tape-and-reel delivery for automated assembly.
Supply support for BC237BRL1 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 manufacturer specializing in energy-efficient power management, analog, sensors, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.
The BC237BRL1 belongs to onsemi's legacy general-purpose bipolar transistor product line, designed specifically for cost-sensitive, high-volume linear amplification and switching applications where reliability, parameter consistency, and Pb-free manufacturability are essential.
FAQ
What is the maximum collector current rating for BC237BRL1?
The BC237BRL1 has a maximum continuous collector current (IC) rating of 100 mA at TA = 25°C. Derating is required above this temperature - power dissipation drops by 2.8 mW/°C. This rating ensures reliable operation in low-power analog and digital interface circuits without external heatsinking.
Does BC237BRL1 have a specified noise figure, and under what conditions?
Yes, BC237BRL1 has a specified noise figure of 4.0 dB measured at IC = 0.2 mA, VCE = 5.0 V, RS = 2.0 kΩ, and f = 1.0 kHz. This value is confirmed in the "ELECTRICAL CHARACTERISTICS" table of the BC237/D Rev. 4 datasheet and supports its use in low-noise microphone and sensor preamplifier designs.
Is BC237BRL1 pin-compatible with BC547B or PN2222A?
BC237BRL1 shares the same TO-92 package and pinout (Collector–Base–Emitter on pins 1–2–3) with BC547B and PN2222A, but it is not a drop-in replacement due to differences in hFE distribution, noise performance, and thermal resistance. Circuit validation is required before substitution, especially in low-noise or thermally constrained designs.
What does the "RL1" suffix indicate in BC237BRL1?
The "RL1" suffix in BC237BRL1 denotes tape-and-reel packaging: 2000 units per reel, oriented per onsemi's standard tape-and-reel specifications (BRD8011/D). It confirms compatibility with pick-and-place equipment and distinguishes it from bulk (5000-unit) or ammo-pack variants like BC237BZL1.
What is the thermal resistance junction-to-ambient (RJA) for BC237BRL1?
The thermal resistance junction-to-ambient (RJA) for BC237BRL1 is 357 °C/W, as specified in the "THERMAL CHARACTERISTICS" section of the BC237/D datasheet. This value assumes standard PCB mounting on FR-4 with minimal copper area - actual RJA improves with added copper pour or thermal vias.
BC237BRL1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-226-3, TO-92-3 Long Body, Formed Leads
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Transistor Type:
- NPN
- Current - Collector (Ic) (Max):
- 100 mA
- Voltage - Collector Emitter Breakdown (Max):
- 45 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:
- 350 mW
- Frequency - Transition:
- 200MHz
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92 (TO-226)
BC237BRL1 FAQ
1.How can I place an order for BC237BRL1 through Aetrix?
Please submit a Request for Quotation (RFQ) for BC237BRL1 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 BC237BRL1 reliable?
The price and inventory of BC237BRL1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC237BRL1 is usually 5 days.
3.What payment methods are accepted for BC237BRL1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC237BRL1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC237BRL1?
BC237BRL1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC237BRL1 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 BC237BRL1?
For technical support, including BC237BRL1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC237BRL1 requirements.
6.How does Aetrix verify that BC237BRL1 is sourced from the original manufacturer or authorized distributors?
All BC237BRL1 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 BC237BRL1 meets industry standards.
7.What is the process for return or replacement of BC237BRL1?
All BC237BRL1 units undergo pre-shipment inspection (PSI). If there is an issue with BC237BRL1, 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 BC237BRL1 part is unused and in its original packaging.
Return procedure for BC237BRL1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BC237BRL1 Tags
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