Logo Search packages:      
Sourcecode: ktechlab version File versions  Download package

jfet.h

/***************************************************************************
 *   Copyright (C) 2005-2006 by David Saxton                               *
 *   david@bluehaze.org                                                    *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 ***************************************************************************/

#ifndef JFET_H
#define JFET_H

#include "matrix.h"
#include "nonlinear.h"

class JFETState
{
      public:
            JFETState();
            void reset();
            
            JFETState operator-( const JFETState & s ) const;
      
            double A[3][3];
            double I[3];
};


class JFETSettings
{
      public:
            JFETSettings();
            
            double V_Th;      ///< zero-bias threshold voltage
            double beta;      ///< transconductance parameter
            double I_S;       ///< gate-junction saturation current
            double N;         ///< gate pn emission coeffecient
            double N_R;       ///< Isr emission coefficient
};


/**
@author David Saxton
 */
00046 class JFET : public NonLinear
{
      public:
            enum JFET_type { nJFET, pJFET };
            
            JFET( JFET_type type );
            virtual ~JFET();
      
00054             virtual Type type() const { return Element_JFET; }
            virtual void update_dc();
            virtual void add_initial_dc();
            JFETSettings settings() const { return m_jfetSettings; }
            void setJFETSettings( const JFETSettings & settings );
      
      protected:
            virtual void updateCurrents();
            /**
             * Calculates the new JFETState from the voltages on the nodes.
             */
            void calc_eq();
            
            void calcIg( double V_GS, double V_GD, double V_DS,
                               double * I_GS, double * I_GD, double * I_DS,
                               double * g_GS, double * g_GD, double * g_DS,
                               double * g_m ) const;
            
            enum OpRegion { NormalCutoff, NormalSaturation, NormalLinear, InverseCutoff, InverseSaturation, InverseLinear };
            OpRegion getOpRegion( double V_DS, double V_GST, double V_GDT ) const;
            
            void updateLim();
            
            JFETState m_os;
            JFETState m_ns;
            int m_pol;
            double V_GS_prev, V_GD_prev;
            double V_lim;
            JFETSettings m_jfetSettings;
            
            static const uint PinD, PinG, PinS;
};

#endif

Generated by  Doxygen 1.6.0   Back to index