Search results
Results from the WOW.Com Content Network
Current gain in the common emitter circuit is obtained from the base and the collector circuit currents. Because a very small change in base current produces a large change in collector current, the current gain (β) is always greater than unity for the common-emitter circuit, a typical value is about 50.
As a result, the common emitter resistor R E acts nearly as a current source. The output voltages at the collector load resistors R C1 and R C3 are shifted and buffered to the inverting and non-inverting outputs by the emitter followers T4 and T5 (shaded blue). The output emitter resistors R E4 and R E5 do not exist in all versions of ECL. In ...
The measurable values of the energy of a quantum system are given by the eigenvalues of the Hamiltonian operator, while its eigenstates give the possible energy states of the system. A value of energy is said to be degenerate if there exist at least two linearly independent energy states associated with it.
In this bipolar junction transistor (BJT) implementation (Figure 4) of the general idea above, a Zener voltage stabilizer (R1 and DZ1) drives an emitter follower (Q1) loaded by a constant emitter resistor (R2) sensing the load current. The external (floating) load of this current source is connected to the collector so that almost the same ...
Examples are imperfect voltage followers (emitter, source, cathode follower, etc.) and amplifiers with series negative feedback (emitter degeneration), whose input impedance is moderately increased. The op-amp non-inverting amplifier is a typical circuit with series negative feedback based on the Miller theorem, where the op-amp differential ...
If Q 1 and Q 2 are matched, that is, have substantially the same device properties, and if the mirror output voltage is chosen so the collector-base voltage of Q 2 is also zero, then the V BE-value set by Q 1 results in an emitter current in the matched Q 2 that is the same as the emitter current in Q 1 [citation needed].
In quantum physics, energy level splitting or a split in an energy level of a quantum system occurs when a perturbation changes the system. The perturbation changes the corresponding Hamiltonian and the outcome is change in eigenvalues ; several distinct energy levels emerge in place of the former degenerate (multi- state ) level.
Any change in output current with output voltage results in a change in the emitter current of Q 3 but very little change in the emitter node voltage. The change in is fed back through Q 2 and Q 1 to the input node where it changes the base current of Q 3 in a way that reduces the net change in output current, thus closing the feedback loop.