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NXP Semiconductors BC639,126
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- Part No.:
- BC639,126
- Manufacturer:
- NXP Semiconductors
- Category:
- Single Bipolar Transistors
- Package:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Datasheet:
-
BC639,126.pdf
- Description:
- TRANS NPN 80V 1A TO-92-3
- Quantity:
- Payment:
- Shipping:
Inventory:7,923
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Product details
Overview
BC639,126 from NXP Semiconductors is an 80 V, 1 A NPN medium power transistor in SOT54A (SC-43A/TO-92 compatible) package, designed for linear voltage regulation, low-side switching, and MOSFET gate driving with DC current gain (hFE) of 63–250 at IC = 150 mA and VCE = 2 V.
For engineers reviewing the BC639,126 datasheet, BC639,126 pinout, BC639,126 application, or BC639,126 equivalent, this discrete transistor supports high-current amplification and robust thermal performance on FR4 PCBs - critical for industrial power control, analog signal conditioning, and driver-stage design where VCEO = 80 V and Ptot = 0.83 W (standard footprint) are key selection criteria.
Technical Context
The BC639,126 operates as a silicon NPN bipolar junction transistor with open-base collector-emitter breakdown voltage (VCEO) rated at 80 V and peak collector current (ICM) up to 1.5 A for tp ≤ 1 ms pulses. Its hFE is binned into two selections (-10: 63–160; -16: 100–250), enabling precise gain matching in amplifier and regulator feedback paths.
Thermal resistance from junction to ambient (Rth(j-a)) is 150 K/W under standard FR4 mounting, while Rth(j-sp) is 40 K/W - confirming suitability for through-hole applications requiring reliable heat dissipation without heatsinks in moderate-power stages.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 80 V - maximum safe collector-emitter voltage with base open; defines upper rail limit in linear regulators and switch-mode drivers. |
| IC | 1 A continuous - sustained collector current capability; supports load switching and driver-stage sourcing without derating at 25 °C. |
| hFE | 63–250 (VCE = 2 V, IC = 150 mA) - wide DC current gain range enables flexible biasing in amplifiers and stable loop gain in voltage regulators. |
| Ptot | 0.83 W (Tamb ≤ 25 °C, FR4 standard footprint) - usable power handling for medium-power discrete stages without forced cooling. |
| fT | 100–180 MHz - transition frequency supporting audio-frequency amplification and fast-switching gate drive applications. |
| VCEsat | ≤ 500 mV (IC = 500 mA, IB = 50 mA) - low saturation voltage minimizes conduction loss in low-side switch configurations. |
| Rth(j-a) | 150 K/W - thermal resistance indicating ~1.3 °C rise per mW on standard FR4; informs board layout and ambient temperature margining. |
Pinout & Package
SOT54A package: plastic single-ended leaded (through-hole) TO-92 compatible outline, 3-lead, JEITA SC-43A / JEDEC TO-92 compliant, with 2.54 mm lead pitch and 5.0 mm body height.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Base | Control terminal for forward-biased B-E junction; requires current-limited drive (IB ≤ 0.2 A peak) to avoid damage. |
| 2 | Collector | Main current-sinking node; electrically connected to case in TO-92 form factor - must be isolated from heatsink if floating. |
| 3 | Emitter | Current return path; tied to ground or low-side reference in common-emitter configurations; establishes VBE bias point. |
Key Features
| Feature | Design Value |
|---|---|
| High current capability | 1 A continuous collector current enables direct drive of small relays, LEDs, and MOSFET gates without external buffering. |
| Two hFE selections | BC639-10 (63–160) and BC639-16 (100–250) allow precision gain matching in differential pairs and feedback networks. |
| High power dissipation | 0.83 W rating on standard FR4 supports operation in unheatsinked linear regulators and Class-A amplifiers up to ~700 mW output. |
| Robust voltage ratings | VCEO = 80 V and VCBO = 100 V provide margin against transients in 24 V and 48 V industrial systems. |
| Low VCEsat | ≤500 mV at IC = 500 mA ensures < 250 mW conduction loss in saturated switch mode - critical for efficiency in driver circuits. |
Applications
| Linear Voltage Regulators | Low-Side Switches |
|---|---|
|
Use Scenario: Discrete pass transistor in adjustable 3-terminal linear regulators delivering up to 1 A at 5–24 V output. IC Role / Device Role / Timing Role: NPN series pass element controlling output voltage via base bias from error amplifier. Use Value: High hFE and 80 V VCEO enable stable regulation across wide input ranges while maintaining low dropout under full load. |
Use Scenario: Ground-referenced switching of resistive or inductive loads (e.g., solenoids, fans) in PLC I/O modules. IC Role / Device Role / Timing Role: Low-side current sink controlled by microcontroller GPIO or logic-level signal. Use Value: 1.5 A ICM and 500 mV VCEsat minimize power loss and thermal stress during repetitive on/off cycling. |
| MOSFET Drivers | Amplifiers |
|
Use Scenario: Gate driver stage for N-channel power MOSFETs in half-bridge motor control or SMPS gate-drive circuits. IC Role / Device Role / Timing Role: Current-amplifying buffer between logic-level controller and MOSFET gate capacitance. Use Value: fT ≥ 100 MHz and 1 A IC support fast turn-on/turn-off of MOSFETs up to ~1 nF gate charge without ringing. |
Use Scenario: Audio preamplifier or sensor signal conditioning stage requiring low-noise, medium-gain amplification. IC Role / Device Role / Timing Role: Common-emitter amplifier with emitter degeneration for linearity and bandwidth control. Use Value: hFE consistency across batches and 180 MHz fT ensure predictable gain-bandwidth product and THD < 1% at 1 kHz. |
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 |
|---|---|---|---|
| BC639-16,126 | Same package and pinout; higher hFE bin (100–250 vs. 63–250 for general BC639); tighter gain distribution. | Better suited for high-loop-gain regulators and precision amplifiers requiring minimal gain variation. | Select when circuit stability depends on consistent hFE > 100 at 150 mA. |
| BC640,126 | PNP complement; identical VCEO (80 V), IC (1 A), and SOT54A package but opposite polarity and inverted pinout (emitter/base swapped). | Used in complementary emitter-follower outputs or high-side switch configurations where PNP topology is required. | Choose only for complementary pair designs - not a functional replacement in NPN-only circuits. |
Compared with BC639,126, the BC639-16,126 offers improved hFE consistency for closed-loop stability, while BC640,126 serves strictly as a polarity-matched complement - neither is pin-compatible nor functionally interchangeable without schematic revision.
Availability
BC639,126 is available at Aetrix Electronics and suitable for linear voltage regulators, low-side switches, and MOSFET drivers requiring stable component supply, long-term obsolescence management, and traceable sourcing for industrial control and embedded power systems.
Supply support for BC639,126 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, automotive processors, and high-performance analog components.
The BC639,126 belongs to NXP's legacy bipolar transistor family designed for industrial power control, analog signal conditioning, and discrete driver applications where reliability, gain consistency, and through-hole manufacturability are essential.
FAQ
What is the package type of BC639,126?
The BC639,126 uses the SOT54A package - a plastic single-ended leaded (through-hole) outline compliant with JEITA SC-43A and JEDEC TO-92 standards, featuring 3 leads, 2.54 mm pitch, and compatibility with standard TO-92 sockets and wave-solder processes.
Does BC639,126 have multiple hFE variants?
Yes, BC639,126 corresponds to the standard BC639 variant with hFE ranging from 63 to 250 at VCE = 2 V and IC = 150 mA. It is distinct from the binned BC639-10 (63–160) and BC639-16 (100–250) versions, which carry separate marking codes (C63910/C63916) and ordering suffixes.
What is the maximum power dissipation of BC639,126?
The BC639,126 has a total power dissipation (Ptot) of 0.83 W when mounted on an FR4 PCB with single-sided copper, tin-plated, and standard footprint - derating linearly above Tamb = 25 °C per the published power derating curve.
Can BC639,126 replace BC639-16,126 in a circuit?
No - BC639,126 and BC639-16,126 are different hFE-binned variants. While both share identical package, voltage/current ratings, and pinout, BC639-16,126 guarantees minimum hFE ≥ 100, whereas BC639,126 covers the full 63–250 range. Substitution may affect loop stability or bias point accuracy.
What is the PNP complement of BC639,126?
The PNP complement of BC639,126 is BC640,126 - same SOT54A package, 80 V VCEO, 1 A IC, and matched thermal characteristics, but with reversed polarity and inverted pinout (emitter and base positions swapped), intended for complementary circuit topologies.
BC639,126 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- NXP Semiconductors
- Series:
- -
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Packaging:
- Tape & Box (TB)
- 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
BC639,126 FAQ
1.How can I place an order for BC639,126 through Aetrix?
Please submit a Request for Quotation (RFQ) for BC639,126 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 BC639,126 reliable?
The price and inventory of BC639,126 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC639,126 is usually 5 days.
3.What payment methods are accepted for BC639,126?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC639,126 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC639,126?
BC639,126 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC639,126 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 BC639,126?
For technical support, including BC639,126 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC639,126 requirements.
6.How does Aetrix verify that BC639,126 is sourced from the original manufacturer or authorized distributors?
All BC639,126 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 BC639,126 meets industry standards.
7.What is the process for return or replacement of BC639,126?
All BC639,126 units undergo pre-shipment inspection (PSI). If there is an issue with BC639,126, 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 BC639,126 part is unused and in its original packaging.
Return procedure for BC639,126:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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