Infineon BC858CE6327 PNP General-Purpose Transistor: Datasheet, Application Circuit, and Replacement Guide
The Infineon BC858CE6327 is a widely used PNP bipolar junction transistor (BJT) housed in a compact SOT-23 surface-mount package. As a fundamental building block in countless electronic circuits, its primary role is to function as an amplifier or a solid-state switch. This article provides a detailed overview of its specifications, a typical application circuit, and guidance for finding a suitable replacement.
Datasheet Overview and Key Specifications
The datasheet for the BC858CE6327 outlines the absolute maximum ratings and electrical characteristics that define its operational limits.
Transistor Type: PNP
Package: SOT-23, a small surface-mount package ideal for high-density PCB designs.
Collector-Emitter Voltage (VCEO): -30 V. This is the maximum voltage that can be applied between the collector and emitter with the base open.
Collector Current (IC): -100 mA. The maximum continuous current that can flow through the collector.
DC Current Gain (hFE): This parameter, which indicates amplification capability, is grouped into gain classes (e.g., A, B, C). The BC858CE6327 typically offers a gain ranging from 125 to 800 at specific test conditions, making it suitable for both low and medium amplification tasks.
Power Dissipation (Ptot): 250 mW. The maximum power the device can dissipate without being damaged.
Transition Frequency (fT): 100 MHz (min). This indicates the frequency at which the transistor's current gain drops to unity, making it useful for low-frequency RF applications and audio amplification.
Typical Application Circuit: PNP Switch
One of the most common uses for the BC858CE6327 is as a low-side switch to control a load such as an LED, relay, or small motor. The circuit configuration is straightforward:
1. The load is connected between the positive supply rail (Vcc) and the transistor's collector.
2. The emitter is connected directly to ground.
3. A base resistor (e.g., 1kΩ to 10kΩ) is essential to limit the base current and is connected between the microcontroller's I/O pin (or other control signal) and the base of the transistor.
4. When the control signal is logic LOW (0V), current flows into the base, biasing the transistor and allowing a larger current to flow from the emitter to the collector, thus turning the load ON.
5. When the control signal is logic HIGH (e.g., 3.3V or 5V), the base-emitter junction is reverse-biased, and the transistor turns OFF, stopping current flow through the load.
This circuit demonstrates the transistor's ability to allow a small control current to switch a much larger load current.
Replacement Guide and Cross-Reference
If the BC858CE6327 is unavailable, several factors must be considered for a suitable replacement:
Polarity: The replacement must be a PNP transistor.
Package: The SOT-23 package is standard, but other similar SMT packages like SC-70 may be considered if PCB space allows.
Key Electrical Characteristics: The replacement's VCEO, IC, and hFE should be equal to or better than the original. Pay close attention to the pinout (Emitter, Base, Collector configuration), as it can vary between manufacturers.
Common direct or near-equivalent replacements include:
BC858B from other manufacturers (e.g., ON Semiconductor, NXP)
2N3906 (in its SOT-23 variant; the through-hole version is extremely common)
MMBT3906
BC807-25
Always consult the respective datasheets to confirm pinout and electrical characteristics before substitution.
ICGOODFIND: The Infineon BC858CE6327 is a versatile and reliable PNP general-purpose transistor perfect for switching and amplification in consumer electronics, industrial controls, and Arduino/Raspberry Pi projects. Its high gain and SMT package make it a go-to component for modern circuit design. When sourcing a replacement, careful cross-referencing of electrical specs and pinouts is crucial for success.
Keywords: PNP Transistor, SOT-23, General-Purpose, Low-Side Switch, Current Gain (hFE)
