From b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b Mon Sep 17 00:00:00 2001
From: priyanka
Date: Wed, 24 Jun 2015 15:03:17 +0530
Subject: initial commit / add all books

---
 135/CH11/EX11.15/EX15.sce | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100755 135/CH11/EX11.15/EX15.sce

(limited to '135/CH11/EX11.15')

diff --git a/135/CH11/EX11.15/EX15.sce b/135/CH11/EX11.15/EX15.sce
new file mode 100755
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+++ b/135/CH11/EX11.15/EX15.sce
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+// Example 11.15: Small signal gain, Input resistance, Output resistance
+clc, clear
+btao=100;
+r_pi=1e3; // in ohms
+ICQ=2.5e-3; // in amperes
+VT=25e-3; // in volts
+gm=ICQ/VT; // Transconductance in mho
+r_pi=btao/gm; // Incremental resistance of emitter-base diode in ohms
+// From ac model without feedback in Fig. 11.47
+RS=10e3; // in ohms
+RF=47e3; // in ohms
+RC=4.7e3; // in ohms
+function[c]=parallel(a,b)
+    c=a*b/(a+b);
+endfunction
+AoL=-gm*parallel(RF,RC)*parallel(RS,parallel(RF,r_pi)); // in ohms
+bta=1/RF;
+T=-bta*AoL;  // Return ratio
+AF=AoL/(1+T); // in ohms
+AVF=AF/RS; // Small signal gain
+RID=parallel(RF,r_pi); // in ohms
+RID_dash=parallel(RID,RS); // in ohms
+RIF_dash_I=RID_dash/(1+T); // in ohms
+RIF_I=RS*RIF_dash_I/(RS-RIF_dash_I); // in ohms
+RIF_dash_V=RS+RIF_I; // in ohms
+RoD_dash=parallel(RF,RC); // in ohms
+RoF_dash=RoD_dash/(1+T); // in ohms
+RoF=RoF_dash*RC/(RC-RoF_dash); // in ohms
+disp(RoF);
+RIF_dash_V=RIF_dash_V*1e-3; // in kilo-ohms
+RoF=RoF*1e-3; // in kilo-ohms
+disp(AVF,"Small signal gain =");
+disp(RIF_dash_V,"Input resistance (kΩ​) =");
+disp(RoF,"Output resistance (kΩ​) =");
\ No newline at end of file
-- 
cgit