The working principle of the protocol chip is that when the voltage added to the triode emission junction is less than the on-voltage of the PN junction, the base current is zero, the collector current and the emitter current are zero, and the triode loses the current amplification effect at this time, and the collector and the emitter are equivalent to the disconnected state of the switch, we call the triode in the cut-off state.
And at a certain appropriate value, the emitter junction of the triode is biased forward, and the collector junction is reversed biased, then the base current plays a control role in the collector current, so that the triode has a current amplification effect
P junction in equilibrium state: P type small semiconductor interface, the carrier diffusion motion will occur. When the equilibrium is reached, the intermediate charge region is formed, the internal electric field 3 is formed and the contact potential vd is formed. The existence of D-giant i prevents most carriers from diffusing to each other, and the dynamic equilibrium is achieved.