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Nexperia USA Inc. BCX51-QX
- Part No.:
- BCX51-QX
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Bipolar Transistors
- Package:
- TO-243AA
- Datasheet:
-
BCX51-QX.pdf
- Description:
- TRANS PNP 45V 1A SOT-89
- Quantity:
- Payment:
- Shipping:
Inventory:1,000
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Product details
Overview
BCX51-Q from Nexperia is a PNP medium-power bipolar junction transistor in SOT89 package, rated for −45 V VCEO, −1 A continuous collector current, and qualified to AEC-Q101 for automotive use. It serves as a high-side switch or linear regulator pass element in battery-powered systems, delivering 1.35 W power dissipation with 6 cm² copper pad and featuring three hFE variants (63–250).
For engineers reviewing the BCX51-Q datasheet, BCX51-Q pinout, BCX51-Q application, or BCX51-Q equivalent, this device is selected for stable high-current PNP switching in thermally constrained automotive and industrial power management circuits where exposed collector thermal pad performance and AEC-Q101 qualification are mandatory.
Technical Context
This PNP transistor operates in linear and saturation regions with verified DC current gain (hFE) of 63–250 at VCE = −2 V and IC = −150 mA, and exhibits VCE(sat) ≤ −0.5 V at IC = −500 mA / IB = −50 mA. Its fT of 145 MHz supports moderate-frequency switching applications.
Thermal design is enabled by an exposed collector pad: Rth(j-a) drops from 250 K/W (standard footprint) to 93 K/W (6 cm² pad), and Rth(j-sp) is 16 K/W - confirming direct thermal path to PCB solder point for reliable power handling.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | −45 V: Maximum safe collector-emitter voltage under open-base condition; defines high-side switch blocking capability. |
| IC | −1 A continuous: Rated DC collector current; supports robust load driving in regulators and MOSFET gate drivers. |
| hFE | 63–250 (at IC = −150 mA): Three factory-sorted gain bins enable precise biasing control in analog and switching circuits. |
| Ptot | 1.35 W (with 6 cm² copper pad): Enables higher sustained power than standard SOT89 devices without active cooling. |
| fT | 145 MHz: Supports fast switching in driver stages and low-noise amplifiers up to mid-VHF range. |
| VCE(sat) | ≤ −0.5 V (IC = −500 mA, IB = −50 mA): Low saturation voltage minimizes conduction loss in high-side switch configurations. |
| Rth(j-a) | 93 K/W (6 cm² pad): Confirmed thermal resistance enables operation up to 125 °C ambient in automotive under-hood environments. |
Pinout & Package
SOT89 (SC-62) plastic surface-mount package with 3 leads, 1.5 mm pitch, 4.5 mm × 2.5 mm × 1.5 mm body, and exposed collector pad for thermal and electrical conduction.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Emitter | Current exit node; connects to load return or ground reference in high-side switch topology. |
| 2 | Collector | Exposed thermal pad and main current sink; must be soldered to ≥6 cm² copper for full 1.35 W rating. |
| 3 | Base | Control input for current amplification; requires series resistor to limit IB ≤ −0.3 A peak. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive under-hood use per stress test standard; eliminates need for requalification in Tier-1 designs. |
| Exposed collector pad | Enables direct thermal coupling to PCB; reduces junction-to-ambient resistance by 63% vs. standard SOT89 footprint. |
| Three hFE variants | BCX51-Q (63–250), BCX51-10-Q (63–160), BCX51-16-Q (100–250); allows gain-matched production without binning overhead. |
| High peak current rating | ICM = −2 A (1 ms pulse); supports surge handling in motor drive and battery protection circuits. |
| Low VBE | ≤ −1 V at IC = −500 mA; reduces base drive power requirement in high-current switching applications. |
Applications
| Linear Voltage Regulators | High-Side Switches |
|---|---|
Use Scenario: Adjustable positive LDO using PNP pass transistor with feedback control loop. IC Role / Device Role / Timing Role: Pass element regulating output voltage by modulating emitter-collector current. Use Value: −45 V VCEO and 1.35 W dissipation support wide-input automotive 12 V/24 V systems with minimal heatsinking. |
Use Scenario: Power rail enable control for microcontroller peripherals or sensors in battery-powered modules. IC Role / Device Role / Timing Role: High-side switch isolating downstream loads from battery during sleep mode. Use Value: −0.5 V VCE(sat) at −500 mA ensures <125 mW conduction loss, extending battery life in always-on applications. |
| Battery-Driven Devices | MOSFET Drivers |
Use Scenario: Reverse-polarity protection and load switching in portable medical or industrial handheld equipment. IC Role / Device Role / Timing Role: PNP-based reverse-voltage blocker and ON/OFF controller for main battery path. Use Value: AEC-Q101 qualification and −5 V VEBO rating ensure reliability across temperature extremes in field-deployed units. |
Use Scenario: Level-shifting gate driver stage for N-channel high-side MOSFETs in half-bridge motor controllers. IC Role / Device Role / Timing Role: Active pull-up transistor charging MOSFET gate capacitance rapidly during turn-on. Use Value: 145 MHz fT and −2 A ICM support <1 µs gate charge times for PWM frequencies up to 100 kHz. |
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 |
|---|---|---|---|
| BCX53-Q | Higher VCEO (−80 V) but lower hFE range (40–250); same SOT89 package and AEC-Q101 qualification. | Better suited for 48 V battery systems or higher-voltage linear regulators where breakdown margin is critical. | Select when system bus voltage exceeds 45 V but thermal constraints remain identical. |
| PN2907A | TO-92 package, −60 V VCEO, −600 mA IC, non-automotive grade; no exposed thermal pad or AEC-Q101 validation. | Limited to low-power, non-automotive consumer or prototyping use due to lower current and thermal capability. | Choose only for cost-sensitive, non-automotive applications where board space and thermal performance are secondary. |
Compared with BCX53-Q, BCX51-Q offers tighter gain control and better thermal performance at lower voltage; versus PN2907A, it delivers 67% higher current, 2.25× power dissipation, and certified automotive reliability - making it the preferred choice for production-grade 12–24 V power management.
Availability
BCX51-Q is available at Aetrix Electronics and suitable for automotive power management, battery protection circuits, and industrial linear regulators requiring stable component supply with AEC-Q101 compliance and SOT89 thermal performance.
Supply support for BCX51-Q 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
Nexperia is a global semiconductor expert focused on essential efficiency-enhancing components, with leadership in logic, discrete, and MOSFET technologies.
The BCX51-Q belongs to Nexperia's AEC-Q101-qualified PNP transistor family, engineered specifically for robust, thermally efficient high-side switching and linear regulation in automotive and industrial power systems.
FAQ
What is the maximum allowable junction temperature for BCX51-Q?
The absolute maximum junction temperature (Tj) is 150 °C, as defined in IEC 60134 limiting values. Operation above this threshold risks permanent degradation. Derating curves in Figure 1 confirm usable power drops to zero at 150 °C ambient when using the standard footprint, so thermal design must maintain Tj ≤ 150 °C under worst-case load and ambient conditions.
Can BCX51-Q replace BCX51-16-Q in a circuit designed for hFE ≥ 100?
No - BCX51-Q has minimum hFE of 63 at IC = −150 mA, while BCX51-16-Q guarantees ≥100 in the same condition. Substituting BCX51-Q may cause insufficient base drive, leading to higher VCE(sat), thermal runaway, or failure to saturate in high-gain-dependent applications like precision current sources.
Is the collector pad electrically isolated from other pins?
No - Pin 2 (collector) is internally and externally connected to the exposed metal pad. This pad must be routed to the collector net and not shorted to ground or other potentials. It serves dual roles: primary current conduction path and thermal interface to the PCB, requiring direct solder connection to a dedicated copper pour.
What is the recommended reflow profile for SOT89 mounting?
Nexperia specifies JEDEC J-STD-020-compliant reflow for SOT89: peak temperature 260 °C for ≤ 30 seconds, with ramp-up ≤ 3 °C/s and ramp-down ≤ 6 °C/s. Figure 10 provides the exact solder land pattern (4.75 mm × 2.25 mm collector pad), and the pad must be fully exposed - no solder mask over the collector area - to achieve specified thermal performance.
BCX51-QX Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- 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:
- 63 @ 150mA, 2V
- Power - Max:
- 500 mW
- Frequency - Transition:
- 145MHz
- Operating Temperature:
- 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-89
BCX51-QX FAQ
1.How can I place an order for BCX51-QX through Aetrix?
Please submit a Request for Quotation (RFQ) for BCX51-QX 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 BCX51-QX reliable?
The price and inventory of BCX51-QX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BCX51-QX is usually 5 days.
3.What payment methods are accepted for BCX51-QX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BCX51-QX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BCX51-QX?
BCX51-QX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BCX51-QX 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 BCX51-QX?
For technical support, including BCX51-QX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BCX51-QX requirements.
6.How does Aetrix verify that BCX51-QX is sourced from the original manufacturer or authorized distributors?
All BCX51-QX 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 BCX51-QX meets industry standards.
7.What is the process for return or replacement of BCX51-QX?
All BCX51-QX units undergo pre-shipment inspection (PSI). If there is an issue with BCX51-QX, 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 BCX51-QX part is unused and in its original packaging.
Return procedure for BCX51-QX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BCX51-QX Tags
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