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NXP Semiconductors BC639,112
- Part No.:
- BC639,112
- Manufacturer:
- NXP Semiconductors
- Category:
- Single Bipolar Transistors
- Package:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Datasheet:
-
BC639,112.pdf
- Description:
- TRANS NPN 80V 1A TO-92-3
- Quantity:
- Payment:
- Shipping:
Inventory:9,248
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Product details
Overview
BC639,112 from NXP Semiconductors is an 80 V, 1 A NPN medium power transistor in TO-92 (SOT54) package, optimized for linear voltage regulation, low-side switching, and MOSFET driver stages. It delivers DC current gain (hFE) of 63–250 at IC = 150 mA, VCE = 2 V, with 80 V VCEO rating and 0.83 W total power dissipation on standard FR4 PCB.
For engineers reviewing the BC639,112 datasheet, BC639,112 pinout, BC639,112 application, or BC639,112 equivalent, key selection criteria include its 80 V collector-emitter breakdown voltage, 1 A continuous collector current capability, dual hFE selections (-10 and -16 variants), thermal resistance of 150 K/W (junction-to-ambient), and compatibility with through-hole assembly in linear regulator and driver circuits.
Technical Context
The BC639,112 operates as a silicon NPN bipolar junction transistor with fixed emitter-base and collector-base junctions, supporting analog amplification and saturated switching. Its design emphasizes high current handling (1 A IC, 1.5 A ICM) and stable DC current gain across temperature, validated per IEC 60134 absolute maximum ratings.
Thermal performance is defined for mounting on FR4 PCB with standard footprint (Rth(j-a) = 150 K/W); no integrated thermal pad or exposed metal tab is present. The device lacks built-in protection features such as ESD clamping or thermal shutdown, requiring external circuit design for safe operation under transient overloads.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 80 V - Maximum collector-emitter voltage before breakdown; enables use in 48 V and lower industrial supply rails with margin. |
| IC | 1 A - Continuous collector current rating; supports medium-power load switching without forced cooling on standard PCB. |
| hFE (IC = 150 mA) | 63–250 - DC current gain range; allows selection of BC639-10 (63–160) or BC639-16 (100–250) for precise biasing in amplifier or driver stages. |
| Ptot | 0.83 W - Total power dissipation at Tamb ≤25 °C on standard FR4; defines thermal headroom before derating begins at ~70 °C ambient. |
| Rth(j-a) | 150 K/W - Junction-to-ambient thermal resistance; determines temperature rise of ~125 °C at full 0.83 W dissipation in still air. |
| fT | 100–180 MHz - Transition frequency; supports small-signal amplification up to VHF band but not RF power applications. |
| VCEsat (IC = 500 mA) | ≤500 mV - Low saturation voltage ensures <0.25 W conduction loss in switch mode, improving efficiency in low-side drivers. |
Pinout & Package
BC639,112 uses the TO-92 (SOT54) plastic through-hole package, with 3 leads and JEDEC-standard outline. Mounting requires standard 0.6 mm lead diameter holes and tin-plated copper traces per NXP's thermal test conditions.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Base | Current-controlled input terminal; requires series resistor to limit IB and ensure reliable saturation or linear operation. |
| 2 | Collector | Main high-current output node; connected to load or supply rail; electrically isolated from case in TO-92 package. |
| 3 | Emitter | Reference terminal for bias network; typically grounded in common-emitter configurations or tied to load return path. |
Key Features
| Feature | Design Value |
|---|---|
| High current capability | 1 A continuous collector current supports direct drive of relays, LEDs, and gate capacitance of power MOSFETs without buffer stages. |
| Two hFE selections | BC639-10 (63–160) and BC639-16 (100–250) variants enable predictable bias point setting in linear regulators and Class-A amplifiers. |
| High power dissipation | 0.83 W rating on standard FR4 allows operation at elevated ambient temperatures when combined with proper trace width and copper area. |
| 80 V VCEO rating | Provides 2× safety margin over 24–48 V industrial bus voltages, reducing risk of avalanche failure during transients. |
| Low VCEsat | ≤500 mV at IC = 500 mA minimizes conduction losses in saturated switching, critical for thermally constrained low-side driver designs. |
Applications
| Linear Voltage Regulators | Low-Side Switches |
|---|---|
Use Scenario: Used as pass transistor in discrete 3-terminal linear regulators delivering up to 1 A output current with adjustable output voltage via feedback divider. IC Role / Device Role / Timing Role: NPN pass element controlling current flow between unregulated input and regulated output rail. Use Value: Enables cost-effective, low-noise regulation without integrated controller ICs; leverages high hFE for minimal base drive requirements. |
Use Scenario: Drives resistive or inductive loads (e.g., solenoids, fans) referenced to ground in industrial control modules. IC Role / Device Role / Timing Role: Saturated NPN switch turning ON/OFF load current with TTL- or microcontroller-compatible base drive. Use Value: Supports 1 A load current with ≤500 mV saturation drop, minimizing heat generation and simplifying thermal management. |
| MOSFET Drivers | Amplifiers |
Use Scenario: Buffers microcontroller GPIO outputs to rapidly charge/discharge gate capacitance of N-channel power MOSFETs in motor drives or SMPS. IC Role / Device Role / Timing Role: Medium-speed current amplifier stage providing >50 mA peak base current to achieve fast MOSFET turn-on/turn-off. Use Value: Delivers 1.5 A peak collector current (ICM) for brief gate-drive pulses, enabling sub-microsecond switching transitions. |
Use Scenario: Configured in common-emitter topology for audio preamplification or sensor signal conditioning in instrumentation systems. IC Role / Device Role / Timing Role: Linear-mode NPN amplifier with DC-coupled or AC-coupled bias network for mid-band signal gain. Use Value: 100–180 MHz fT and stable hFE support bandwidth up to ~10 MHz with low distortion in Class-A operation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN medium power transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BC639-16,112 | Higher hFE range (100–250 vs. 63–160 for BC639-10); identical VCEO, IC, package, and thermal specs. | Better suited for low-base-drive applications like high-gain preamps or low-current linear regulators where precise gain control is needed. | Select BC639-16,112 when higher DC gain improves stability or reduces required base current; otherwise BC639-10,112 suffices for general-purpose switching. |
| BC640,112 | PNP complement with matching VCEO (80 V), IC (1 A), and SOT54 package; same hFE ranges and thermal characteristics. | Used in complementary emitter-follower or push-pull output stages where PNP sourcing capability is required alongside BC639 sinking. | Choose BC640,112 only when building symmetrical output stages; not a functional replacement for BC639,112 in NPN-specific roles. |
Compared with BC639-16,112 and BC640,112, the BC639,112 offers the baseline hFE selection for general-purpose NPN switching and amplification, while maintaining identical voltage, current, and thermal limits-making it the default choice unless higher gain or complementary polarity is explicitly required.
Availability
BC639,112 is available at Aetrix Electronics and suitable for linear voltage regulators, low-side switches, and MOSFET drivers requiring stable component supply, long-term obsolescence planning, and consistent parametric performance across production batches.
Supply support for BC639,112 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
NXP Semiconductors is a global semiconductor company headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and consumer applications.
The BC639,112 belongs to NXP's legacy bipolar transistor family designed for cost-sensitive, medium-power analog and switching functions in industrial control, power management, and interface circuits.
FAQ
What is the maximum collector-emitter voltage rating for BC639,112?
The BC639,112 has a maximum collector-emitter voltage (VCEO) rating of 80 V under open-base conditions. This value is specified in Table 2 and Table 6 of the NXP datasheet and represents the absolute maximum voltage the device can withstand before breakdown. Exceeding this rating risks permanent damage, and design margins should be applied for reliability in real-world transients.
Does BC639,112 have different hFE variants, and how do they differ?
Yes, BC639,112 corresponds to the standard BC639 part, which is available in two hFE selections: BC639-10 (63–160) and BC639-16 (100–250), both tested at VCE = 2 V and IC = 150 mA. The BC639,112 marking code aligns with the BC639-10 variant per Table 5. These selections allow designers to choose predictable DC gain for stable biasing in amplifiers or regulators without additional gain-setting components.
What package type is used for BC639,112, and what are its mechanical identifiers?
BC639,112 uses the TO-92 package, designated by NXP as SOT54 (JEITA SC-43A, JEDEC TO-92). It is a plastic through-hole package with three leads, 5.2 mm body width, 14.5 mm length, and 0.45 mm lead diameter. Pin 1 is Base, Pin 2 is Collector, and Pin 3 is Emitter - confirmed in Table 3 and Figure 14 of the datasheet.
Can BC639,112 be used in surface-mount designs?
No, BC639,112 is exclusively offered in the through-hole SOT54 (TO-92) package. While related devices like BCP56 (SOT223) and BCX56 (SOT89) provide surface-mount alternatives with similar electrical specs, BC639,112 itself has no SMT variant. Migration to SMT requires redesigning the footprint and selecting a functionally comparable part such as BCX56 or BCP56.
What is the thermal resistance and power dissipation capability of BC639,112?
BC639,112 has a junction-to-ambient thermal resistance (Rth(j-a)) of 150 K/W when mounted on a standard FR4 PCB with single-sided copper and tin plating (Table 7). Its total power dissipation (Ptot) is rated at 0.83 W at Tamb ≤25 °C (Table 6), derating linearly above that temperature per Figure 1. This defines its usable power envelope in natural-convection environments.
BC639,112 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- NXP Semiconductors
- Series:
- -
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Transistor Type:
- NPN
- Current - Collector (Ic) (Max):
- 1 A
- Voltage - Collector Emitter Breakdown (Max):
- 80 V
- Vce Saturation (Max) @ Ib, Ic:
- 500mV @ 50mA, 500mA
- Current - Collector Cutoff (Max):
- 100nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 63 @ 150mA, 2V
- Power - Max:
- 830 mW
- Frequency - Transition:
- 180MHz
- Operating Temperature:
- 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92-3
BC639,112 FAQ
1.How can I place an order for BC639,112 through Aetrix?
Please submit a Request for Quotation (RFQ) for BC639,112 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 BC639,112 reliable?
The price and inventory of BC639,112 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC639,112 is usually 5 days.
3.What payment methods are accepted for BC639,112?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC639,112 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC639,112?
BC639,112 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC639,112 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 BC639,112?
For technical support, including BC639,112 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC639,112 requirements.
6.How does Aetrix verify that BC639,112 is sourced from the original manufacturer or authorized distributors?
All BC639,112 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 BC639,112 meets industry standards.
7.What is the process for return or replacement of BC639,112?
All BC639,112 units undergo pre-shipment inspection (PSI). If there is an issue with BC639,112, 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 BC639,112 part is unused and in its original packaging.
Return procedure for BC639,112:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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