BD249C-S - 100V 25A NPN Power Transistor | Bourns
N.º de pieza: BD249C-S ✓ Activo| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $2.1 | $2,10 |
| 10 | $1.89 | $18,90 |
| 100 | $1.55 | $155,00 |
| 500 | $1.32 | $660,00 |
| 1.000 | $1.1 | $1.100,00 |
BD249C-S Descripción general
An NPN bipolar junction power transistor (BJT) is a current-controlled semiconductor switch and amplifier in the broader device hierarchy: BJT -> bipolar transistor -> discrete power semiconductor. Power BJTs remain widely used in linear power amplifiers, low-frequency switching, and general-purpose power amplification where ruggedness and low cost outweigh the efficiency of modern MOSFETs.
Key features of the BD249C-S include the 100 V collector-emitter rating (the C voltage-suffix grade, the highest in the BD249 A/B/C series), 25 A continuous / 40 A peak collector current capability, 125 W dissipation at 25 C case temperature with a derating factor above 25 C, and a transition frequency of 3 MHz per DigiKey parametric data. The epoxy package meets UL 94 V-0 at 0.125 inch thickness, and Pb-free packaging is available within the family.
The device is designed for complementary use with the BD250 series PNP transistors at 25 C case temperature, enabling symmetric push-pull output stages. Typical applications include general-purpose power amplifiers, audio output stages, power supplies, motor control, and low-frequency switching circuits. Its high current rating makes it well suited to driving heavy inductive and resistive loads.
Design considerations: as a bipolar device, the BD249C-S requires base drive current proportional to collector current; plan for adequate heatsinking because the 125 W rating applies only at 25 C case temperature. Always verify the safe operating area against your load line, especially for inductive loads.
This page adds value beyond the datasheet by synthesizing distributor inventory data, cross-referenced drop-in alternatives, comparison tables, and practical design notes in one place.
Alternativas directas para BD249C-S — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Variantes de esta serie
Modelos de la misma serie compatibles directamente con BD249C-S (mismo factor de forma y huella) — difiere en Flammability Rating, Package, Transistor Type.
Herramienta de comparación rápida — seleccione piezas alternativas para compararlas lado a lado:
BD249B-S
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
BD249A-S
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
BD249C
✅ Sustitución directa✓ En stock
$1.82 / unidad
Ver hoja de datos →2SD1841
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
2SD1842
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
BD249C-S Valores máximos y características eléctricas
| Tipo de transistor | NPN Bipolar Junction Transistor (BJT) |
| Tensión colector-emisor (Vceo) | 100 V |
| Collector-Base Voltage (VCB) | 100 V |
| Emitter-Base Voltage (VEB) | 5 V |
| Collector Current (Continuous) | 25 A |
| Collector Current (Peak) | 40 A |
| Total Power Dissipation (TC = 25 C) | 125 W |
| Power Derating | 1.0 W/C above 25 C case temperature |
| Frecuencia de transición (ft) | 3 MHz |
| Encapsulado | SOT-93 (TO-218), 3 pins, through hole |
| Tipo de montaje | Through Hole |
| Recuento de pines | 3 |
| Series Grade | BD249C (C grade, highest VCEO in BD249 series) |
| Complementary Device | BD250 series (PNP) |
| ESD Rating (HBM) | Class 3B, > 8000 V (per onsemi BD249C family data) |
| Flammability Rating | UL 94 V-0 @ 0.125 in (epoxy, family data) |
Configuración de pines de BD249C-S
| Pin 1 | Base — Base control terminal (current input) |
| Pin 2 | Collector — Collector terminal, connected to metal tab/case |
| Pin 3 | Emitter — Emitter terminal (current output) |
Aplicaciones típicas
BD249C-S es adecuado para 6 aplicacións: General-Purpose Power Amplifiers, Linear Power Supplies, Motor Control and Drivers, Audio Output Stages (Hi-Fi and PA Systems), Low-Frequency Switching Circuits, Inverter and Converter Output Stages.
General-Purpose Power Amplifiers
The BD249C-S is explicitly specified by Bourns for general-purpose power amplifier and switching applications, and its 100 V collector-emitter rating supports amplifier supply rails well above the 50 V level common in professional audio power amplifiers. In a class-AB output stage, the BD249C-S NPN is paired with a BD250C PNP complementary device to source and sink load current symmetrically. The 25 A continuous collector current rating provides substantial margin into low-impedance loads, and the 125 W dissipation rating (25 C case) accommodates the significant quiescent and signal-dependent losses inherent to linear output stages. Adequate heatsinking and bias stabilization are essential since dissipation scales with signal level.
Recomendado
Linear Power Supplies
In series-pass linear regulator applications, the BD249C-S operates as the pass element between the unregulated input and the regulated output. Its 100 V VCEO accommodates high-voltage input buses, and the 25 A continuous rating covers high-current supplies for industrial equipment, electroplating, and battery chargers. Because the pass transistor dissipates (VIN - VOUT) x ILOAD continuously, the 1.0 W/C derating above 25 C case temperature must be respected and a conservatively sized heatsink with low thermal resistance selected. The 3 MHz transition frequency is immaterial in DC pass service, while the rugged bipolar construction tolerates the surge and startup transient conditions that linear supplies routinely encounter.
Recomendado
Motor Control and Drivers
The BD249C-S serves as a low-side switch or linear driver in DC motor control circuits, where its 40 A peak collector current rating absorbs motor inrush and stall currents that far exceed steady-state operating current. In PWM-driven configurations the 3 MHz fT supports switching frequencies into the tens of kilohertz, though bipolar saturation and storage-time effects generally limit practical PWM rates to below 20 kHz for efficiency. Flyback or freewheel diodes are mandatory with inductive motor loads to keep flyback voltage spikes within the 100 V VCEO rating. Base drive must be scaled to maintain saturation at full load current per the datasheet hFE curves.
Recomendado
Audio Output Stages (Hi-Fi and PA Systems)
The BD249 family was designed for complementary use with the BD250 series specifically with audio output stages in mind, making the BD249C-S a natural fit for hi-fi amplifiers and public-address systems. In quasi-complementary or fully complementary symmetry configurations, the 100 V grade permits supply rails up to roughly +/-45 V while retaining margin, enabling output powers in the 100-200 W class into 8 ohm loads when devices are paralleled with emitter ballast resistors. The TO-218 package mounts directly to standard audio amplifier heatsink extrusions. Thermal tracking of the bias network with the output device heatsink prevents thermal runaway, the classic pitfall of bipolar output stages.
Recomendado
Low-Frequency Switching Circuits
As a general-purpose power switch, the BD249C-S handles resistive and inductive loads at currents up to 25 A continuous and 40 A peak, including solenoids, relays, heaters, and lamp loads. The device is driven into saturation with base current sized per the datasheet forced-beta recommendation, typically forcing a beta of 10 for reliable saturation. The 100 V VCEO provides headroom against inductive kick when combined with appropriate suppression networks such as flyback diodes or snubbers. ESD robustness noted in the family data (HBM class 3B, greater than 8000 V) adds handling margin during assembly. Switching losses rise with frequency, so duty cycles and repetition rates should be kept within the safe operating area.
Recomendado
Inverter and Converter Output Stages
The BD249C-S can be employed in low-frequency square-wave inverters, battery-charger converters, and UPS output stages where its high voltage rating (100 V) and high current capability (25 A) suit 12 V, 24 V, and 48 V DC bus systems. Its 3 MHz transition frequency accommodates the multi-kilohertz switching typical of such designs, though designers should evaluate bipolar turn-off storage time when computing switching losses and dead-time margins. Paralleling multiple devices with individual emitter ballast resistors extends current capability for high-power inverters. Complementary pairing with BD250 PNP devices simplifies half-bridge and push-pull topologies by enabling direct NPN/PNP output pairs without level-shifting drive transformers.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para BD249C-S — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | BD249B-S | BD249A-S | BD249C | 2SD1841 | 2SD1842 |
|---|---|---|---|---|---|---|
| Package | SOT-93 (TO-218), 3-pin through hole | SOT-93 (TO-218) - same | SOT-93 (TO-218) - same | SOT-93 (TO-218) - same | SOT-93 (TO-218) - same | SOT-93 (TO-218) - same |
| Brand | Bourns | Bourns | Bourns | onsemi | Renesas Electronics | Renesas Electronics |
| Polarity | NPN | NPN | NPN | NPN | NPN | NPN |
Diferenciadores clave
- Highest voltage grade in the BD249 family (frente a BD249B-S)
- Highest continuous current rating versus lower-current same-package alternatives (frente a BD246C-S)
- Multi-source availability through industry-standard BD249C designation (frente a 2SD1841)
Notas de diseño
The 125 W power dissipation rating of the BD249C-S applies only at a 25 C case temperature, which in practice requires a heatsink with near-zero thermal resistance. The datasheet specifies derating of 1.0 W per degree C above 25 C case temperature. Estimated: for 40 W dissipation with a target junction of 125 C and a typical power-stage thermal stack, the case would need to stay near 85 C or below, which requires a large forced-air heatsink. Size the heatsink from the actual junction-to-case thermal resistance in the Bourns datasheet, not from the 125 W headline number.
As a bipolar junction transistor, the BD249C-S is current-driven: base current must be provided continuously at a level that keeps the device in saturation (switching) or in the desired linear operating region (amplifier/pass element). Near the 25 A full-load rating, use a conservative forced beta (for example, force beta of 10) when sizing base drive, because hFE falls significantly at high collector current. Verify the actual hFE curves in the Bourns datasheet; the hFE value for this ordering code was not available in the source data for this page.
With inductive loads (motors, solenoids, transformer primaries), always fit a flyback diode or snubber across the load. Inductive switching can transiently exceed the 100 V VCEO rating and destroy the device through avalanche or secondary breakdown. For linear amplifier duty, ensure the DC and AC load lines remain inside the forward-bias safe operating area (SOA) at the maximum expected case temperature - bipolar power transistors are far less forgiving of reactive load lines than MOSFETs. Also verify the E-B voltage limit of 5 V is never exceeded in reverse during drive waveforms.
The SOT-93/TO-218 package includes a mounting hole for mechanical attachment to a heatsink. Use a thermal interface material (grease or phase-change pad) and torqued fastener per the datasheet mechanical drawing; dry mounting can add tens of degrees of case-to-heatsink thermal resistance. Keep base-drive traces short and adequately wide, and provide heavy copper pours or bus connections for collector and emitter paths carrying up to 25 A continuous to minimize resistive heating on the PCB.
Información de cumplimiento
Family datasheet notes a Pb-free package is available and epoxy meets UL 94 V-0 @ 0.125 in; device-specific RoHS/REACH status of the BD249C-S ordering code must be confirmed with Bourns.
