Introduction
The BD204 is a PNP silicon power transistor designed for medium-power amplification and switching applications, commonly used in audio amplifier output stages, regulator circuits, and complementary push-pull designs. Its high breakdown voltage and robust power handling make it suitable for circuits requiring the negative side of the waveform to be driven. According to the datasheet, BD204 is the PNP complement to BD203.
The BD204 is a PNP silicon power transistor designed for medium-power amplification and switching applications, commonly used in audio amplifier output stages, regulator circuits, and complementary push-pull designs. Its high breakdown voltage and robust power handling make it suitable for circuits requiring the negative side of the waveform to be driven. According to the datasheet, BD204 is the PNP complement to BD203.
BD204 PNP Transistor
Because of its low saturation voltage, wide safe operating area, and symmetric complementary matching with NPN counterparts, the BD204 is favored in high-fidelity audio amplifiers, linear power supply circuits, and power control circuits. Its design aims to deliver clean output and reliable operation under moderate current and voltage stress.
Pinout of BD204
Key Features
- Suitable for PNP side of complementary amplifier output stages
- Low collector-emitter saturation voltage
- Wide safe operating area
- Excellent thermal stability and mechanical robustness
- Matched complementary pairing with BD203
- Robust for both audio and switching applications
Specifications/Characteristics
- Collector-Emitter Breakdown Voltage (Vceo): –60 V
- Collector-Base Breakdown Voltage (Vcbo): –60 V
- Emitter-Base Breakdown Voltage (Vebo): –5 V
- Continuous Collector Current (Ic): –8 A
- Non-repetitive Peak Collector Current (Icm): –12 A
- Total Power Dissipation (Ptot): 60 W (with proper heatsink)
- DC Current Gain (hFE) minimum: 30 (under specified test conditions)
- Operating Junction Temperature: –65 °C to +150 °C
- Package: TO-220 / PNP power transistor
Pin Configuration
| Pin# | Pin Name | Pin Description |
|---|---|---|
| 1 | Base | Controls transistor conduction when base is driven lower than emitter |
| 2 | Collector | Main current-carrying terminal connected to load or heatsink |
| 3 | Emitter | Current flows out toward negative side in PNP operation |
Comparison Summary: BD203 vs BD204
- BD203 is an NPN power transistor intended for the positive half of output stages, while BD204 is its PNP complement intended for the negative half in symmetrical amplifier designs.
- Both share similar voltage and current ratings but operate with opposite polarity in circuits: BD203 conducts when its base is positive relative to its emitter, BD204 conducts when its base is negative relative to its emitter.
- In amplifier output stages, BD203 and BD204 are used together to drive both halves of the audio waveform, reducing distortion and improving signal symmetry.
- BD203 handles the positive swing, BD204 handles the negative swing, allowing a balanced push-pull output with high fidelity.
More Circuit Layouts
Key Applications of BD204 PNP Transistor
- Push-pull audio amplifier output stages
- Complementary amplifier designs (paired with BD203)
- Linear regulators and power supply control
- Negative side switching circuits
- Hi-fi audio power systems
- Power amplifier driver circuits
NPN Complimentary Transistor
- The NPN complementary transistor for BD204 is BD203. The BD204 is designed to complement BD203 in amplifier output stages.
Equivalent Transistors of BD204 PNP Transistor
- BD202 (lower voltage variant in same family)
- BDX78 (same series PNP power transistor)
- TIP42 (for lower power PNP alternatives)
- MJ2955 (for higher current PNP alternative)
- 2N2907 (for small-signal PNP substitution in low-power circuits)
(Pin configuration of some transistors mentioned here may different from BD204).
Datasheet of BD204 PNP Transistor
Click the following Button below to download the datasheet of BD204 Transistor :
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