Hi I am a beginner in electronics stuffs (inparticular, transistor) I would like to know whats the "threshold" of VCE when the NPN works from stauration to linear region. The Ic I am using is ~50mA at most. I believe the threshod of VCE is ~0.3V Am I right? pls reply to my email as well Thanks ! PCF
A transistor is still active and fully operational at zero volts collector to base, and partly active even with small forward biasing. One needs toforward bias the collector-base region sufficently to then "flip" the operation to inverted mode where the collector acts as an emitter and vice-versa. Such operation has been used to achieve lower than "normal" on voltage drops, especially in signal choppers. Most transistors have a very crummy beta in the inverted mode, and can run from 1E-3 to a high of 0.10 . However, there are some high forward beta transistors that also have inverted betas that exceed one and may get as high as 50 (!!), made by Zetex; the ZTX696B is an NPN with beta (min) of 500, and the ZTX718 is a PNP with beta (min) of 300. As i remember, their reverse beta is rather spetacular when compared with ordinary transistors.
