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onsemi BC237BZL1
- Part No.:
- BC237BZL1
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-226-3, TO-92-3 Long Body, Formed Leads
- Datasheet:
-
BC237BZL1.pdf
- Description:
- TRANS NPN 45V 0.1A TO92
- Quantity:
- Payment:
- Shipping:
Inventory:7,378
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Product details
Overview
BC237BZL1 from onsemi is an NPN silicon small-signal amplifier transistor in TO-92 package, rated for VCEO = 45 V, IC = 100 mA, PD = 350 mW at TA = 25°C, with hFE = 120–200 (at IC = 10 mA, VCE = 5 V), used in audio preamplifier stages and low-power switching circuits.
For engineers reviewing the BC237BZL1 datasheet, pinout, applications, or equivalent options, key selection criteria include DC current gain range, VCE(sat) ≤ 0.2 V at IC/IB = 10, fT ≥ 150 MHz, thermal resistance RJA = 357 °C/W, and Pb-free ammo-pack packaging compatibility with manual and semi-auto assembly.
Technical Context
The BC237BZL1 operates as a general-purpose NPN bipolar junction transistor optimized for linear amplification and low-speed switching. Its design emphasizes stable hFE across collector currents from 0.2 mA to 100 mA and low noise figure (NF = 4.0 dB at IC = 0.2 mA, f = 1 kHz), with Cobo = 4.5 pF and Cibo = 8.0 pF enabling RF-capable mid-band operation up to ~200 MHz.
It features a fixed three-terminal structure with defined base-emitter and collector-emitter junctions, supporting common-emitter configurations. Thermal performance is governed by RJA = 357 °C/W and RJC = 125 °C/W, requiring heatsinking only above ~200 mW dissipation in still air. The device is not rated for automotive AEC-Q101 stress testing or high-reliability mil-spec use.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 45 V - Maximum safe collector-to-emitter voltage before breakdown under open-base condition; defines upper rail limit in amplifier bias networks. |
| IC (max) | 100 mA - Continuous collector current limit; sets maximum load drive capability in switching or Class-A amplifier designs. |
| hFE | 120–200 - DC current gain range at IC = 10 mA, VCE = 5 V; determines required base drive for target collector current. |
| VCE(sat) | 0.2 V max - Saturation voltage at IC/IB = 10; directly impacts power loss and logic-level compatibility in switch applications. |
| fT | 150 MHz - Current-gain bandwidth product at IC = 0.5 mA; indicates usable frequency limit for small-signal amplification. |
| RJA | 357 °C/W - Junction-to-ambient thermal resistance; defines temperature rise per watt dissipated without heatsink. |
| NF | 4.0 dB - Noise figure at IC = 0.2 mA, f = 1 kHz; critical for low-noise preamp stage selection in audio signal chains. |
Pinout & Package
BC237BZL1 uses the industry-standard TO-92 (Case 29-11, Style 17) plastic package with 3 leads, lead-free plating, and 2000-unit ammo-pack packaging for manual or semi-automated insertion.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Collector | Main current output terminal; connects to supply rail or load in common-emitter configuration; carries full collector current. |
| 2 | Base | Control input terminal; requires precise current limiting (e.g., series resistor) to set operating point and avoid thermal runaway. |
| 3 | Emitter | Current return path; typically grounded or connected to emitter resistor for bias stabilization in amplifier designs. |
Key Features
| Feature | Design Value |
|---|---|
| Pb-free construction | Complies with RoHS Directive 2011/65/EU; enables environmentally compliant PCB assembly without leaded solder process constraints. |
| Low saturation voltage | VCE(sat) ≤ 0.2 V ensures <10 mW conduction loss at 100 mA, improving efficiency in battery-powered switching circuits. |
| Stable hFE over temperature | hFE maintains 120–200 range from −55°C to +125°C, reducing need for gain-compensation circuitry in industrial environments. |
| Low noise performance | NF = 4.0 dB at 1 kHz supports clean signal amplification in microphone preamps and sensor interface front-ends. |
Applications
| Audio Preamp Stage | Low-Speed Switching |
|---|---|
Use Scenario: Amplifying weak signals from electret microphones or piezoelectric sensors in consumer voice recorders. IC Role / Device Role / Timing Role: Small-signal NPN amplifier in common-emitter configuration with emitter degeneration for linearity. Use Value: hFE = 120–200 and NF = 4.0 dB enable >60 dB SNR at 1 kHz, while VCE(sat) ≤ 0.2 V minimizes distortion near signal zero-crossings. | Use Scenario: Driving LED indicators or relays from microcontroller GPIO pins in industrial control panels. IC Role / Device Role / Timing Role: Low-power saturated switch with fixed base drive resistor network. Use Value: IC = 100 mA rating and VCE(sat) ≤ 0.2 V allow direct 3.3 V/5 V MCU interfacing with <10 mW switching loss per channel. |
| Signal Coupling Buffer | DC Bias Generator |
Use Scenario: Isolating impedance between analog filter stages in active crossover networks for loudspeakers. IC Role / Device Role / Timing Role: Unity-gain emitter-follower buffer providing high input impedance and low output impedance. Use Value: fT = 150 MHz ensures flat response to 20 kHz with <0.1 dB gain error, while Cobo = 4.5 pF prevents high-frequency loading of preceding stage. | Use Scenario: Generating stable reference current for op-amp biasing or current-source loads in precision instrumentation. IC Role / Device Role / Timing Role: Fixed-current sink using base-emitter voltage regulation and emitter resistor feedback. Use Value: VBE(on) = 0.62 V (typ) and hFE stability enable ±3% current accuracy over −40°C to +85°C without trimming. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN small-signal amplifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BC237BRL1 | Same die, TO-92 tape-and-reel packaging (2000 pcs); identical electrical specs and thermal ratings. | Optimized for automated pick-and-place; no functional difference in circuit behavior. | Select BC237BRL1 for SMT-line integration; BC237BZL1 remains preferred for manual prototyping or low-volume hand assembly. |
| BC237BG | Pb-free variant in bulk packaging (5000 pcs); same hFE, VCEO, and fT; differs only in RoHS compliance marking and shipping format. | Suitable for high-volume production where bulk handling and RoHS traceability are mandatory. | Choose BC237BG when procurement requires full RoHS documentation and cost-per-unit optimization at scale. |
Compared with BC237BRL1 and BC237BG, the BC237BZL1 offers identical transistor performance but distinct logistics advantages: ammo-pack packaging enables rapid manual placement and reduces component damage during handling, making it optimal for engineering validation and pilot builds where flexibility outweighs automation efficiency.
Availability
BC237BZL1 is available at Aetrix Electronics and suitable for audio preamplifiers, low-speed switching circuits, and DC bias generators requiring stable component supply, consistent parametric performance, and RoHS-compliant packaging.
Supply support for BC237BZL1 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 focused on energy-efficient electronics, delivering discrete, analog, and logic solutions for automotive, industrial, and cloud infrastructure markets.
The BC237 series belongs to onsemi's general-purpose bipolar transistor product line, designed for cost-sensitive, high-volume applications demanding reliable small-signal amplification and switching performance across commercial and industrial temperature ranges.
FAQ
What is the maximum collector-emitter voltage rating for BC237BZL1?
The BC237BZL1 has a maximum collector-emitter voltage rating (VCEO) of 45 V under open-base conditions at TA = 25°C. This value is confirmed in the Absolute Maximum Ratings table of the official BC237/D datasheet Rev. 4. Exceeding this voltage risks irreversible junction breakdown. Derating is required above 25°C ambient, with no specified linear derating coefficient provided for VCEO in the document.
Does BC237BZL1 support Pb-free soldering processes?
Yes, BC237BZL1 is a Pb-free device compliant with RoHS Directive 2011/65/EU. Its marking includes the "G" suffix per onsemi's ordering nomenclature, and its packaging uses lead-free plating compatible with standard reflow profiles (e.g., J-STD-020). The BC237BZL1 datasheet explicitly references ON Semiconductor's Pb-Free strategy and soldering guidelines in Section 1.
What is the typical DC current gain (hFE) of BC237BZL1 at 10 mA collector current?
The BC237BZL1 exhibits a typical DC current gain (hFE) of 150 at IC = 10 mA, VCE = 5 V, and TA = 25°C, with a guaranteed minimum of 120 and maximum of 200. This range is specified in the Electrical Characteristics table of the BC237/D datasheet and applies directly to the BC237B variant, which BC237BZL1 implements.
Can BC237BZL1 be used in RF amplifier applications?
The BC237BZL1 has an fT of 150 MHz at IC = 0.5 mA, VCE = 3 V, indicating usable small-signal gain up to approximately 20–30 MHz in practical amplifier designs. While not optimized for VHF/UHF, it supports HF band receivers and IF stages where low noise (NF = 4.0 dB) and moderate gain are prioritized over ultra-wide bandwidth. Layout parasitics must be minimized for stable RF operation.
What is the thermal resistance from junction to ambient (RJA) for BC237BZL1?
The BC237BZL1 has a thermal resistance from junction to ambient (RJA) of 357 °C/W when mounted on a standard FR-4 PCB with minimal copper area, as specified in the Thermal Characteristics section of the BC237/D datasheet. This value assumes natural convection cooling and defines the temperature rise per watt dissipated-e.g., 350 mW operation yields ~125°C junction rise above ambient.
BC237BZL1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-226-3, TO-92-3 Long Body, Formed Leads
- Packaging:
- Bulk
- 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)
BC237BZL1 FAQ
1.How can I place an order for BC237BZL1 through Aetrix?
Please submit a Request for Quotation (RFQ) for BC237BZL1 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 BC237BZL1 reliable?
The price and inventory of BC237BZL1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC237BZL1 is usually 5 days.
3.What payment methods are accepted for BC237BZL1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC237BZL1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC237BZL1?
BC237BZL1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC237BZL1 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 BC237BZL1?
For technical support, including BC237BZL1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC237BZL1 requirements.
6.How does Aetrix verify that BC237BZL1 is sourced from the original manufacturer or authorized distributors?
All BC237BZL1 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 BC237BZL1 meets industry standards.
7.What is the process for return or replacement of BC237BZL1?
All BC237BZL1 units undergo pre-shipment inspection (PSI). If there is an issue with BC237BZL1, 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 BC237BZL1 part is unused and in its original packaging.
Return procedure for BC237BZL1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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