The resistor in base to gnd. (transistor)

[Boki]

Hi All,

Always a resistor about 10Kohm to GND in front of base, is that a
resistor to draw out the parasitical capacitance in transistor (Vf) ?

Thank you very much for lesson.


Best regards,
Boki.

 

[Rene Tschaggelar]

Hi All,

Always a resistor about 10Kohm to GND in front of base, is that a
resistor to draw out the parasitical capacitance in transistor (Vf) ?

Thank you very much for lesson.

Depending on speed and on other parameters,
it can be lower, say 500 Ohms.

Rene

 

[Jon]

The resistor gives the leakage current ICeo somewhere to go.
Otherwise, at high temperatures the transistor could turn itself on.
Also, with a restor from base to emitter, the Vce voltage breakdown
value is increased to somewhere between Vceo and Vces.