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Diodes Incorporated BCX51TA
- Part No.:
- BCX51TA
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Bipolar Transistors
- Package:
- TO-243AA
- Datasheet:
-
BCX51TA.pdf
- Description:
- TRANS PNP 45V 1A SOT-89-3
- Quantity:
- Payment:
- Shipping:
Inventory:2,671
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Product details
Overview
BCX51TA from Diodes Incorporated is a PNP medium-power bipolar junction transistor in SOT89 package, rated for -45V VCEO, -1A continuous collector current, and VCE(sat) < -500mV at -500mA/–50mA drive-used in AF output stages and medium-power switching circuits in industrial power supplies and audio amplifiers.
For engineers reviewing the BCX51TA datasheet, BCX51TA pinout, BCX51TA application, or BCX51TA equivalent, key selection criteria include verified VCEO rating, thermal resistance (RθJA = 125°C/W on 15mm × 15mm 1oz Cu), hFE range (25–250), complementary NPN pairing (BCX54), and RoHS-compliant "Green" packaging.
Technical Context
This PNP transistor operates with emitter-grounded configuration, supporting linear amplification and saturated switching modes. Its DC current gain spans 25–250 across IC = –5mA to –500mA at VCE = –2V, and transition frequency fT reaches 150MHz at IC = –50mA/VCE = –10V.
Thermal performance is defined by RθJL = 13°C/W (junction-to-lead) and RθJC = 27°C/W (junction-to-case), enabling stable operation up to +150°C junction temperature. ESD robustness includes 4kV HBM and 1kV CDM ratings per JEDEC JS-001/JS-002.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | –45 V - Maximum allowable collector-emitter voltage before breakdown under open-base condition; defines safe operating voltage headroom in switching applications. |
| IC (continuous) | –1 A - Continuous DC collector current capability; supports medium-power load driving without derating at TA ≤ 25°C with adequate copper area. |
| VCE(sat) | < –500 mV @ –500 mA/–50 mA - Low saturation voltage ensures minimal conduction loss and heat generation in switch-mode operation. |
| hFE | 25–250 - DC current gain range across operating conditions; enables predictable base drive sizing for both linear and switching use cases. |
| fT | 150 MHz - Gain-bandwidth product at IC = –50 mA/VCE = –10 V; supports high-frequency amplification up to low-VHF band. |
| RθJA | 125 °C/W - Junction-to-ambient thermal resistance on 15mm × 15mm 1oz Cu PCB; determines required board layout for thermal management. |
| ESD HBM | 4000 V - Human Body Model rating per JEDEC JS-001; indicates robustness against handling-induced electrostatic discharge. |
Pinout & Package
Package: SOT89 - Surface-mount plastic package with exposed collector pad for enhanced thermal dissipation; dimensions per Diodes outline SOT89 (D = 4.50 mm, E = 2.50 mm, H = 4.10 mm); UL 94V-0 rated molding compound.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Emitter) | Emitter terminal | Current exit path in PNP operation; connected to higher potential node in common-emitter configurations. |
| 2 (Base) | Control terminal | Input for forward-biasing the base-emitter junction; requires negative current relative to emitter to turn on device. |
| 3 (Collector) | Collector terminal / Thermal pad | Main current sink; electrically and thermally connected to exposed metal pad-must be soldered to copper pour for thermal compliance. |
Key Features
| Feature | Design Value |
|---|---|
| Low VCE(sat) | < –500 mV at –500 mA ensures ≤0.25 W conduction loss, reducing heatsink requirements in 12V/24V power control stages. |
| High fT | 150 MHz enables use in wideband AF amplifiers and fast-switching PWM drivers up to ~10 MHz fundamental frequency. |
| Thermal design support | RθJL = 13°C/W allows direct thermal coupling to PCB copper; enables >1W steady-state dissipation with 50mm × 50mm 1oz Cu layout. |
| Automotive-ready qualification path | Manufactured in IATF 16949-certified facilities; PPAP-capable with AEC-Q101 change control available upon request for automotive-grade variants. |
| Halogen- and antimony-free | <900 ppm Br, <900 ppm Cl, <1000 ppm Sb compounds-meets strict environmental compliance for industrial and consumer end equipment. |
Applications
| Audio Power Output Stage | DC-DC Converter Switch |
|---|---|
|
Use Scenario: Final amplification stage in Class-B or Class-AB audio amplifiers delivering 0.5–2W into 4–8Ω loads. IC Role / Device Role / Timing Role: PNP complement in push-pull output pair; provides current sinking during negative half-cycle of audio signal. Use Value: Low VCE(sat) minimizes crossover distortion and thermal drift; hFE consistency across temperature supports stable biasing. |
Use Scenario: High-side or low-side switch in non-isolated buck or boost converters operating at ≤500 kHz switching frequency. IC Role / Device Role / Timing Role: Medium-power switching element controlling energy transfer between inductor and load; driven by PWM controller via base resistor network. Use Value: 150 MHz fT and fast saturation enable clean turn-on/turn-off edges; RθJL = 13°C/W supports compact thermal layout. |
| Industrial Relay Driver | Linear Voltage Regulator Pass Element |
|
Use Scenario: Driving 12V/24V electromagnetic relays with coil currents up to 800mA in PLC I/O modules and motor control panels. IC Role / Device Role / Timing Role: Current amplifier interfacing microcontroller GPIO to relay coil; operated in saturation for minimal power loss. Use Value: –1A IC rating and –2A ICM handle relay inrush; VCE(sat) < –500mV limits self-heating during sustained activation. |
Use Scenario: Series pass transistor in adjustable linear regulators supplying 0.5–1A to analog sensor front-ends or precision DACs. IC Role / Device Role / Timing Role: Voltage-controlled current source regulating output by dissipating excess input-output differential voltage. Use Value: 2.0W max power dissipation (on 50mm × 50mm Cu) supports 5V dropout at 1A; hFE stability ensures consistent regulation under load transients. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar PNP medium-power transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BCX52TA | VCEO = –60 V (vs. –45 V); otherwise identical pinout, package, and gain characteristics. | Better suited for 48V industrial bus interfaces where higher voltage margin is required. | Select when system rail exceeds 36V or transient overvoltage risk demands ≥20% headroom above nominal supply. |
| MJD2955G | TO-220 package, higher IC = –10A, VCEO = –60V, but larger footprint and no SOT89 compatibility. | Used in high-current linear regulators or motor drivers where thermal mass and heatsink mounting are feasible. | Choose only if board space allows TO-220 and thermal design accommodates higher power dissipation without SMT constraints. |
Compared with BCX52TA, BCX51TA offers tighter voltage margin for cost-sensitive 24V systems; versus MJD2955G, it delivers SMT scalability and lower assembly cost at the expense of absolute current headroom and heatsink flexibility.
Availability
BCX51TA is available at Aetrix Electronics and suitable for audio output stages, DC-DC converter switches, industrial relay drivers, and linear regulator pass elements requiring stable component supply, full traceability, and long-term lifecycle support.
Supply support for BCX51TA 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
Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design, manufacturing, and sales operations across Asia, Europe, and the Americas.
The BCX51TA belongs to Diodes' legacy bipolar transistor family designed for medium-power switching and amplification in industrial, consumer, and automotive-qualified applications-emphasizing reliability, thermal efficiency, and RoHS compliance.
FAQ
What is the maximum continuous collector current for BCX51TA?
The BCX51TA supports –1 A continuous collector current at TA = +25°C with proper PCB copper area (15mm × 15mm 1oz Cu). Derating applies above 25°C ambient: power dissipation drops linearly to zero at +150°C case temperature per the datasheet's derating curve.
Is BCX51TA pin-compatible with BCX54?
No-BCX51TA is a PNP transistor in SOT89 with emitter-base-collector pinout (1-2-3), while BCX54 is its complementary NPN counterpart with identical SOT89 package but reversed polarity and opposite pin function logic; they are functionally paired but not pin-swappable without circuit redesign.
Does BCX51TA require a heatsink in typical applications?
A dedicated heatsink is not required for BCX51TA in most applications; its exposed collector pad is designed for direct thermal coupling to PCB copper. With ≥25mm × 25mm 1oz Cu, it sustains 1.5W continuously; heatsinking becomes necessary only above 2W dissipation or in sealed, high-ambient environments.
What is the meaning of "AA" marking on BCX51TA devices?
"AA" is the Diodes Incorporated product type marking code for BCX51 devices in SOT89 package, laser-etched on the top surface. It distinguishes BCX51TA from BCX52TA (AE) and BCX53TA (AH), and confirms correct variant identification during automated optical inspection and manual verification.
BCX51TA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- TO-243AA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Transistor Type:
- PNP
- Current - Collector (Ic) (Max):
- 1 A
- Voltage - Collector Emitter Breakdown (Max):
- 45 V
- Vce Saturation (Max) @ Ib, Ic:
- 500mV @ 50mA, 500mA
- Current - Collector Cutoff (Max):
- 100nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 40 @ 150mA, 2V
- Power - Max:
- 1 W
- Frequency - Transition:
- 150MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-89-3
BCX51TA FAQ
1.How can I place an order for BCX51TA through Aetrix?
Please submit a Request for Quotation (RFQ) for BCX51TA 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 BCX51TA reliable?
The price and inventory of BCX51TA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BCX51TA is usually 5 days.
3.What payment methods are accepted for BCX51TA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BCX51TA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BCX51TA?
BCX51TA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BCX51TA 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 BCX51TA?
For technical support, including BCX51TA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BCX51TA requirements.
6.How does Aetrix verify that BCX51TA is sourced from the original manufacturer or authorized distributors?
All BCX51TA 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 BCX51TA meets industry standards.
7.What is the process for return or replacement of BCX51TA?
All BCX51TA units undergo pre-shipment inspection (PSI). If there is an issue with BCX51TA, 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 BCX51TA part is unused and in its original packaging.
Return procedure for BCX51TA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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