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A MOSFET version of Figure 3 is shown in Figure 4, where MOSFETs M 3 and M 4 operate in ohmic mode to play the same role as emitter resistors R E in Figure 3, and MOSFETs M 1 and M 2 operate in active mode in the same roles as mirror transistors Q 1 and Q 2 in Figure 3. An explanation follows of how the circuit in Figure 3 works.
A modified version of the cascode can also be used as a modulator, particularly for amplitude modulation. The upper device supplies the audio signal, and the lower is the RF amplifier device. High-voltage stack. A cascode may also be combined with a voltage ladder to form a high-voltage transistor.
Fig. 1: Wilson current mirror Fig. 2: Wilson current source. There are three principal metrics of how well a current mirror will perform as part of a larger circuit. The first measure is the static error, i.e., the difference between the input and output currents expressed as a fraction of the input current.
One trick is to add a common-gate (current-follower) stage to make a cascode circuit. The current-follower stage presents a load to the common-source stage that is very small, namely the input resistance of the current follower (R L ≈ 1 / g m ≈ V ov / (2I D) ; see common gate). Small R L reduces C M. [2]
List of free analog and digital electronic circuit simulators, available for Windows, macOS, Linux, and comparing against UC Berkeley SPICE.The following table is split into two groups based on whether it has a graphical visual interface or not.
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:
Cascode Voltage Switch Logic (CVSL) refers to a CMOS-type logic family which is designed for certain advantages. It requires mainly N-channel MOSFET transistors to implement the logic using true and complementary input signals, and also needs two P-channel transistors at the top to pull one of the outputs high.
In other words, the input current "programs" the output one and the whole circuit serves as a programmed current source (current-controlled or dependent current source). Obviously, in order to do that, such a current direction inverter (having a more popular name – current mirror ) has to be at least a 3-terminal device (Fig. 2).