electronics/simulation/bjt.h

0001 /***************************************************************************
0002  *   Copyright (C) 2003-2005 by David Saxton                               *
0003  *   david@bluehaze.org                                                    *
0004  *                                                                         *
0005  *   This program is free software; you can redistribute it and/or modify  *
0006  *   it under the terms of the GNU General Public License as published by  *
0007  *   the Free Software Foundation; either version 2 of the License, or     *
0008  *   (at your option) any later version.                                   *
0009  ***************************************************************************/
0010
0011 #ifndef BJT_H
0012 #define BJT_H
0013
0014 #include "nonlinear.h"
0015
0016 class BJTState
0017 {
0018 public:
0019     BJTState();
0020     void reset();
0021
0022     BJTState operator-(const BJTState &s) const;
0023
0024     double A[3][3];
0025     double I[3];
0026 };
0027
0028 class BJTSettings
0029 {
0030 public:
0031     BJTSettings();
0032
0033     double I_S; ///< saturation current
0034     double N_F; ///< forward emission coefficient
0035     double N_R; ///< reverse emission coefficient
0036     double B_F; ///< forward beta
0037     double B_R; ///< reverse beta
0038 };
0039
0040 /**
0041 @author David Saxton
0042 */
0043 class BJT : public NonLinear
0044 {
0045 public:
0046     BJT(bool isNPN);
0047     ~BJT() override;
0048
0049     Type type() const override
0050     {
0051         return Element_BJT;
0052     }
0053     void update_dc() override;
0054     void add_initial_dc() override;
0055     BJTSettings settings() const
0056     {
0057         return m_bjtSettings;
0058     }
0059     void setBJTSettings(const BJTSettings &settings);
0060
0061 protected:
0062     void updateCurrents() override;
0063
0064     /**
0065      * Calculates the new BJTState from the voltages on the nodes.
0066      */
0067     void calc_eq();
0068     void calcIg(double V_BE, double V_BC, double *I_BE, double *I_BC, double *I_T, double *g_BE, double *g_BC, double *g_IF, double *g_IR) const;
0069     void updateLim();
0070
0071     BJTState m_os;
0072     BJTState m_ns;
0073     int m_pol;
0074     double V_BE_prev, V_BC_prev;
0075     double V_BE_lim, V_BC_lim;
0076     BJTSettings m_bjtSettings;
0077 };
0078
0079 #endif