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Current in the reference transistor Q 1 is held constant, thereby fixing the compliance voltage. Plots assume I C1 = 10 mA, V A = 50 V, V CC = 5 V, I S = 10 fA, β 1, = 100 independently of current. The current dependence of the resistances r π and r O is discussed in the article hybrid-pi model. The current dependence of the resistor values is:
Figure 2: Adding an emitter resistor decreases gain, but increases linearity and stability. Common-emitter amplifiers give the amplifier an inverted output and can have a very high gain that may vary widely from one transistor to the next. The gain is a strong function of both temperature and bias current, and so the actual gain is somewhat ...
Figure 1: An ideal current source, I, driving a resistor, R, and creating a voltage V. A current source is an electronic circuit that delivers or absorbs an electric current which is independent of the voltage across it. A current source is the dual of a voltage source. The term current sink is sometimes used for sources fed from a negative ...
The Wilson current mirror achieves the high output impedance of equation (6) by negative feedback rather than by emitter degeneration as cascoded mirrors or sources with resistor degeneration do. The node impedance of the only internal node of the mirror, the node at the emitter of Q 3 and the collector of Q 2, is quite low. [3]
See also an example of a mirror with emitter degeneration to increase mirror resistance. For the simple mirror shown in the diagram, typical values of will yield a current match of 1% or better. Figure 2: An n-channel MOSFET current mirror with a resistor to set the reference current I REF; V DD is positive voltage.
The theorems are useful in 'circuit analysis' especially for analyzing circuits with feedback [1] and certain transistor amplifiers at high frequencies. [ 2 ] There is a close relationship between Miller theorem and Miller effect: the theorem may be considered as a generalization of the effect and the effect may be thought as of a special case ...
— Omegatron 18:52, 1 February 2006 (UTC) Only took about a year, but I finally got around to it :) Klunky was VERY useful and easy to use BTW, thanks. Roger 15:49, 27 April 2007 (UTC) This really needs more than one diagram. We need to show emitter degeneration, typical biasing methods, etc. — Omegatron 14:29, 31 May 2007 (UTC)
The transistor continuously monitors V diff and adjusts its emitter voltage to equal V in minus the mostly constant V BE (approximately one diode forward voltage drop) by passing the collector current through the emitter resistor R E. As a result, the output voltage follows the input voltage variations from V BE up to V +; hence the name ...