The BC817-40W is an NPN transistor designed for general AF applications. It offers high collector current, high current gain, and a low collector-emitter saturation voltage. Its complementary type is the BC807 (PNP).
| Parameter | Symbol | Test conditions | MIN | MAX | UNIT |
| Collector-Base Voltage | VCBO | IC= 10A, IE=0 | 50 | V | |
| Collector-Emitter Voltage | VCEO | IC= 10mA, IB=0 | 45 | V | |
| Emitter-Base Voltage | VEBO | IE= 1A, IC=0 | 5 | V | |
| Collector Current -Continuous | IC | 0.5 | A | ||
| Collector Power Dissipation | PC | TA=25 | 0.3 | W | |
| Junction Temperature | Tj | 150 | |||
| Storage Temperature | Tstg | -55 | 150 | ||
| Collector Cut-off Current | ICBO | VCB= 45 V, IE=0 | 0.1 | A | |
| Emitter Cut-off Current | IEBO | VEB=4V, IC=0 | 0.1 | A | |
| DC Current Gain | hFE(1) | VCE=1V, IC=100mA | 100 | 600 | |
| hFE(2) | VCE=1V, IC=500mA | 40 | |||
| Collector-Emitter Saturation Voltage | VCE(sat) | IC= 500mA, IB= 50mA | 0.7 | V | |
| Base-Emitter Saturation Voltage | VBE(sat) | IC= 500mA, IB= 50mA | 1.2 | V | |
| Base-Emitter Voltage | VBE | VCE= 1 V, IC= 500mA | 1.2 | V | |
| Collector Capacitance | Cob | VCB=10V, f=1MHz | 10 | pF | |
| Transition Frequency | fT | VCE= 5 V, IC= 10mA f=100MHz | 100 | MHz |