spice a guide to circuit simulation and analysis using pspice

[...]... referred to as the dc steady state On the other hand, if the magnitude of each nondependent source can be written as K sin ð!t þ Þ, where K is a constant, then the resulting steady state is known as the sinusoidal steady state, and well-known frequency-domain, or phasor, methods are applicable in its analysis In general, electronic circuit analysis is a combination of dc and sinusoidal steady-state analysis, ... voltage-current relationships (1.1) to (1.3), Kirchhoff’s laws are sufficient to formulate the simultaneous equations necessary to solve for all currents and voltages of a network (We use the term network to mean any arrangement of circuit elements.) Kirchhoff’s voltage law (KVL) states that the algebraic sum of all voltages around any closed loop of a circuit is zero; it is expressed mathematically as... Element Name Signal Type Control Source Value Resistor R:::  Inductor L::: H Capacitor C::: Voltage source F V::: a AC or DC Vb Current source I::: AC or DCa Ab VCVS E::: ðcn1 ; cn2 Þ V/V CCVS H::: V::: V /A VCCS G::: ðcn1 ; cn2 Þ A/ V CCCS F::: V::: A/ A a Time-varying signal types (SIN, PULSE, EXP, PWL, SFFM) also available b AC signal types may specify phase angle as well as magnitude 1.4 CIRCUIT LAWS Along... CIRCUIT ANALYSIS: PORT POINT OF VIEW 7 ´ Example 1.5 Use SPICE methods to determine the Thevenin equivalent circuit looking to the left through terminals 3,0 for the circuit of Fig 1-7 Fig 1-7 In SPICE independent source models, an ideal voltage source of 0 V acts as a short circuit and an ideal current source of 0 A acts as an infinite impedance or open circuit Advantage will be taken of these two features... 2 (a) Network B YN 2 (b) (c) Fig 1-4 The´venin’s theorem states that an arbitrary linear, one-port network such as network A in Fig 1-4 (a) can be replaced at terminals 1,2 with an equivalent series-connected voltage source VTh and impedance ZTh (¼ RTh þ jXTh Þ as shown in Fig 1-4(b) VTh is the open -circuit voltage of network A at terminals 1,2 and ZTh is the ratio of open -circuit voltage to short -circuit. .. Thevenin impedance ZTh is found as the equivalent impedance for the circuit to the left of terminals 1,2 with the independent sources deactivated (that is, with VA replaced by a short circuit, and IA replaced by an open circuit) : ZTh ¼ RTh ¼ R1 þ R2 ¼ 2 þ 3 ¼ 5  ´ Example 1.4 In the circuit of Fig 1-6 (a) , VA ¼ 4 V,  ¼ 0:25 A= V, R1 ¼ 2 , and R2 ¼ 3  Find the Thevenin equivalent voltage and impedance for... the voltage across or current through any passive element may be found as the algebraic sum of the individual voltages or currents due to each of the independent sources acting alone, with all other independent sources deactivated An ideal voltage source is deactivated by replacing it with a short circuit An ideal current source is deactivated by replacing it with an open circuit In general, controlled... terminals that are of interest Thus, V13 is the voltage across terminals 1 and 3, where terminal 1 is at a higher potential than terminal 3 Similarly, I13 is the current that flows from terminal 1 to terminal 3 As an example, VL in Fig 1-6 (a) could be labeled V12 (but not V21 ) Note also that an active element (either independent or controlled) is restricted to its assigned, or stated, current or voltage,... short -circuit current that flows from terminal 1 to terminal 2 due to network A, and YN is the ratio of short -circuit current to open -circuit voltage at terminals 1,2 with network B disconnected If network A or B contains a controlled source, its controlling variable must be in that same network It is apparent that YN  1=ZTh ; thus, any method for determining ZTh is equally valid for finding YN CHAP 1] CIRCUIT. .. CIRCUITS At some (sufficiently long) time after a circuit containing linear elements is energized, the voltages and currents become independent of initial conditions and the time variation of circuit quantities becomes identical to that of the independent sources; the circuit is then said to be operating in the steady state If all nondependent sources in a network are independent of time, the steady state . 0-07-136270-3 All trademarks are trademarks of their respective owners. Rather than put a trademark symbol after every occur- rence of a trademarked name, we use names in an editorial fashion only, and to. parameters can be numerically evaluated by SPICE methods. In electron- ics applications, the z and h parameters find application in analysis when small ac signals are impressed on circuits that. frequency-domain, or phasor, methods are applicable in its analysis. In general, electronic circuit analysis is a combination of dc and sinusoidal steady-state analysis, using the principle of