PSPICE 计算机仿真 Simulation Program with Integrated Circuit Emphasis

CH3 DC SWEEP ANALYSIS 直流扫描分析

3.1 Sweeping a single source

Fig.26

Example 2 For the circuit shown in Fig.26, use PSpice to find the values of i o and v o when v g varies from 0 to 100V in 10V steps.(P22)

Fig.27

Place->Part Analog lib: R Source lib: Vsrc, Isrc Special lib: Iprint (ammeter 安培表 ) Special lib: Vprint2 (voltmeter 伏特表 )

注意事项 : Vsrc 元件 : 参数不需要改动 Isrc 元件 : 选中 Isrc 元件, ( 粉色表示被选中 !) Edit->Properties … 修改 DC 项 : 5, 如图 27a

Fig.27a 修改 Isrc 属性

Iprint 元件需要执行 Mirror 操作 : : 选中 Iprint 元件, ( 粉色表示被选中 !) Edit->Mirror->Horizontally H 执行 Mirror 操作 Edit->Properties … 修改 DC 项 : Y, 如图 28

Fig.28 修改 Iprint 属性

Vprint2 元件需要执行 Mirror 操作 : 选中 Vprint2 元件, ( 粉色表示被选中 !) Edit->Mirror->Horizontally H 执行 Mirror 操作 Edit->Properties … 修改 DC 项 : Y, 如图 28a

Fig.28a 修改 Vprint2 属性

Fig.29 Simulation Settings dialog

What does Probe do? We can also depict the results of the DC Sweep analysis graphically, using Probe.

PSpice->Run( 如图 29a) View->Output file( 如图 30)

Fig.29a Probe 窗口

Fig.30 Output file

Trace/Add Trace （ Fig.31 ） 注意： Trace Expression: V2(R1)

Fig.31 Selecting a variable: V2(R1)

Fig.32 the resulting plot

3.2 Sweep Multiple Sources

Example 3 The current source in the circuit shown in Fig.26 varies from 0 to 5A in 1A steps. For each value of the source voltage, plot i 0 as v g varies from 0 to 100V in steps of 20V.

Solution The schematic is the same as the one in Fig.27. In Capture, select the menu option PSpice/Edit Simulation Settings to specify a Secondary Sweep, the additional sweep variable and its values Fig.33.

Fig.33 Simulation Settings dialog 2

We also changed the increment in the Primary Sweep from 10V to 20V(Fig.33a).

Fig. 33a Simulation Settings dialog 1

Trace/Add Trace （ Fig.33b ） 注意： Trace Expression: I(R4)

Fig.33b Selecting a variable: I(R4)

Fig.34 the resulting plot? (It may be wrong! Please check!)