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BC856 SMD PNP Transistor Data
Key transistor data for the BC856 PNP switching & general amplifier transistor including key electrical parameters, pinout, package type and many other key transistor datasheet details.
There are several transistors in the series, BC856, and the BC857, BC858, BC859, and BC860. They are designed as PNP epitaxial silicon transistors for switching and amplifier applications.
These transistors are complementary to the BC846, BC847, BC848, and BC850 series of NPN transistors.
They are stated as being suitable for automatic insertion in thick and thin film circuits (as well as normal SMT PCBs.
The BC856 is the high voltage device in this series having a VCEO of -65 volts and a VCBO of -80 volts.
Key datasheet details and performance parameters for the BC856 transistor.
| BC856 transistor datasheet parameters & data |
|
|---|---|
| Parameters | Details |
| Transistor type | PNP switching & amplifier |
| Package type | SOT-23 |
| Transistor SMD Ident** | 9AA, 9AC, 9AC |
| VCBO max (V) | -80 |
| VCEO max (V) | -65 |
| VEBOmax (V) | -5 |
| VCEsat (V) | 90mV typ @ I 250mV @ 100mA |
| IC max (mA) | -100 |
| TJ Max °C | 150 |
| PTOT mW | 310 |
| fT min (MHz) | 150 |
| COB | 6pF typical |
| hfe | see below |
| IC for hfe | |
| Similar / equivalents | |
Outline & pinout:
** Transistor SMD identification:
In view of the fact that it is not possible to fully mark surface mount transistors with their full part number a short form identification or marking is added to the package.
This is typically a three character identification. For the BC859 this is either 9AA, 9AB, or 9AC - these are for the different hFE classifications.
Explanation of transistor parameters
| Parameter | Explanation |
|---|---|
| VCBO Max | Maximum collector-base voltage with emitter open circuit . |
| VCEO Max | Maximum collector-emitter voltage with base open circuit. |
| VEBO Max | Maximum emitter-base voltage with collector open circuit. |
| VCEsat (included where applicable) | The voltage drop across the collector-emitter when the transistor is fully saturated (acting as a closed switch). |
| IC Max | Maximum collector current. |
| Parameter | Explanation |
|---|---|
| TJ | Maximum junction temperature. |
| PTOT Max | Maximum device dissipation normally in free air at 25°C unless other conditions indicated. |
| fT Min | Minimum cutoff frequency at which the current gain in a common emitter circuit falls to unity. |
| COB Max | Maximum collector capacitane, normally measured with emitter open circuit. |
| hFE | DC current gain for HFE at IC. [Note hfe is the small signal gain and although this may be slightly different, the transistor current gain will vary considerably from ne transistor to the next of the same type.] |
| PTOT Max | Maximum device dissipation normally in free air at 25°C unless other conditions indicated. |
These are the main transistor parameters that have been included in our list. There are others, but these help quantify the main elements of the performance of the transistor.
Please note, that the data given is the best estimate we can give within a tabulated summary of this nature. Parameters also vary between manufacturers. Electronics Notes cannot accept any responsibility for errors, inaccuracies, etc, although we do endevaour to ensure the data is as accurate as possible.
Notes and supplementary information
The BC856 is a popular surface mount PNP silicon transistor in a surface mount SOT23 package. It is the high voltage device in this range in terms of its maximum operating voltages, with other transistors in the series having lower maximum voltage ratings.
• Availability & sources
The device is available from a number of stockists and electronic component distributors.
• hFE for variants
The BC857 has three variants according to the gain, A: 110 - 220, B: 200 - 450, C: 420 - 800.
The suffixes A, B or C are added to the overall part number so that the required selection can be made, and the SMD markings are 9AA, 9AB, or 9AC in order for the different gain values.
• Noise performance
The BC856 is a standard transistor in the series in terms of its noise performance. Although it is not particularly low noise, figures for this are given in the datasheet.
The noise performance is specified as being between 2 (typical) and 10 dB maximum with a VCE of 5V collector current Ic of 100µA, RG of 2kΩ and f = 1 kHz.
These figures are not at all bad, but this device is most likely o be selected for its high voltage performance rather than its noise performance. That said, it is always good to have the noise performance defined in the datasheet.
Written by Ian Poole .
Experienced electronics engineer and author.
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