BD433 Transistor NPN
14,64 EGP
High-Current BD433 NPN Transistor for Low-Voltage Power Tasks
The BD433 Transistor functions as a high-performance NPN Silicon Bipolar Junction Transistor (BJT) specifically designed for applications requiring high current at low operating voltages. While it maintains the compact TO-126 footprint, its internal construction is optimized to handle significantly more current than standard medium-power transistors. Consequently, it is a primary choice for engineers designing battery-powered motor controllers, high-current relay drivers, and portable power tools.
Robust 4-Ampere Performance and Efficiency
Specifically, the BD433 manages a continuous collector current ($I_C$) of up to 4A, with a peak capacity of 7A. This impressive rating allows the device to drive high-torque DC motors, heavy-duty solenoids, and large-scale LED arrays with ease. Furthermore, the transistor handles a collector-emitter voltage ($V_{CEO}$) of up to 22V. This rating provides a stable operating margin for 6V, 12V, and 18V battery systems. Moreover, its low saturation voltage (typically 0.5V at 2A) ensures high energy efficiency by minimizing heat generation during full conduction. Transitioning to the BD433 ensures your low-voltage power management stages remain thermally stable under heavy-duty loads.
Versatile TO-126 Package and Thermal Reliability
Additionally, the BD433 utilizes the industry-standard TO-126 (SOT-32) package style. This design features a convenient central mounting hole, which allows you to bolt the transistor directly to a heat sink or a metal chassis for improved thermal dissipation. Specifically, while the device handles 1.25W in free air, it can dissipate up to 36W when properly heat-sinked.
Moreover, technicians frequently install the BD433 in the output stages of automotive electronics and high-current linear regulators. Specifically, its DC current gain ($h_{FE}$) remains stable across a wide range of currents, ensuring predictable performance in analog designs. Furthermore, because it features NPN polarity, it integrates seamlessly into ground-referenced switching configurations. Additionally, the component is the NPN complement to the BD434 PNP transistor. Using these two together allows for the creation of high-current H-bridge motor controllers or balanced push-pull configurations.
Verified Data Sheet (Technical Specifications)
| Feature | Specification |
| Transistor Polarity | NPN |
| Collector-Emitter Voltage ($V_{CEO}$) | 22V |
| Collector-Base Voltage ($V_{CBO}$) | 22V |
| Emitter-Base Voltage ($V_{EBO}$) | 5V |
| Collector Current ($I_C$) | 4.0A |
| Peak Collector Current ($I_{CM}$) | 7.0A |
| Total Power Dissipation ($P_{tot}$) | 1.25W (Free Air) / 36W (with Heat Sink) |
| DC Current Gain ($h_{FE}$) | 85 to 375 (Group 10, 16, or 25) |
| Transition Frequency ($f_T$) | 3.0 MHz (Min) |
| Package Type | TO-126 (SOT-32) |
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