Test: Characteristics Of Npn Bipolar Transistors - Electrical Engineering (EE) MCQ

Transconductance gm of a bipolar transistor is given by gm = Ic/(kT/q). Transconductance is the electrical characteristic relating the current through the output of a device to the voltage across the input of a device.

Transconductance gm is independent of process.

Transconductance gm is exponentially dependent on input voltage Vbe ( base to emitter voltage).

 Transconductance gm is directly proportional to Ic, collector current.

 Transconductance gm is a weak function of transistor size.

Transconductance gm of bipolar is greater than gm of MOS if inputs are controlled by equal amounts of charge.

Cg(MOS) = Cbase(bipolar) when inputs are controlled by equal amounts of charge, and then gm(bipolar) >> gm(MOS).

Current/Area (I/A) of bipolar is five times better than CMOS and this can be calculated using base resistance and base transit time.

 Bipolar transistors exhibits tun-on, turn-off, storage delays.

In bipolar transistor, emitter region is heavily doped and base region is lightly doped.