Contents
How do you calculate the resistance of a BJT?
The output resistance of the common-emitter amplifier is just Rout = RC. To see this, consider Figure 5.40 on page 199 of Razavi.
How do I select a transistor in Ltspice?
Before adding the command, right-click the transistor and press the “Pick New Transistor” button. Make sure that in the SPICE model column that the transistor has a beta factor to edit (will be called bf=# or BF=# in that line somewhere).
How do you find the input and output resistance of a BJT?
BJT Amplifier Input/Output Impedance Input impedance is defined as the ratio of imput voltage to input current. It is calculated from the AC equivalent circuit as the equivalent resistance looking into the input with all current cources replaced by an open and all voltage sources replaced by a short.
How to plot a parameter against something other than LTspice?
Open a new schematic in LTspice, insert LT3092 symbol by pressing the ‘F2’ function key and finish drawing the schematic and labeling the nets as follows. 2. Right click on the schematic and edit the simulation command to the following.
What are the ohmic resistances of the Spice BJT?
The Spice BJT model is illustrated schematically in Fig. 4.2. The ohmic resistances of the base, collector, and emitter regions of the BJT are lumped into three linear resistances r B, r C and r E , respectively.
When to use LTspice in a transient analysis?
A common use for LTSpice ® is to run a time domain transient analysis where a parameter (e.g. voltage or current) can be plotted against time. Occasionally, you may wish to know the behavior of a circuit versus another parameter such as resistance.
What kind of circuits can be simulated In LTspice?
The types of circuits that will be simulated will range from single npn and pnp transistor amplifiers to multiple-transistor amplifier circuits, as well as circuits that utilize the transistor as an on-off switch. Two statements are required to describe any particular semiconductor device to LTSpice.