/***************************************************************************
 *   Copyright (C) 2003-2004 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 DIODE_H
#define DIODE_H

#include "nonlinear.h"

class DiodeSettings
{
	public:
		DiodeSettings();
		void reset();
		
		double I_S;	///< Diode saturation current
		double N;	///< Emission coefficient
		double V_B;	///< Reverse breakdown
// 		double R;	///< Series resistance
};


/**
This simulates a diode. The simulated diode characteristics are:

@li I_s: Diode saturation current
@li V_T: Thermal voltage = kT/4 = 25mV at 20 C
@li n: Emission coefficient, typically between 1 and 2
@li V_RB: Reverse breakdown (large negative voltage)
@li G_RB: Reverse breakdown conductance
@li R_D: Base resistance of diode

@short Simulates the electrical property of diode-ness
@author David Saxton
*/
class Diode : public NonLinear
{
	public:
		Diode();
		virtual ~Diode();
	
		virtual void update_dc();
		virtual void add_initial_dc();
		virtual Element::Type type() const { return Element_Diode; }
		DiodeSettings settings() const { return m_diodeSettings; }
		void setDiodeSettings( const DiodeSettings & settings );
		/**
		 * Returns the current flowing through the diode
		 */
		double current() const;
	
	protected:
		virtual void updateCurrents();
		void calc_eq();
		void calcIg( double V, double * I, double * g ) const;
		void updateLim();
		
		double g_new, g_old;
		double I_new, I_old;
		double V_prev;
		double V_lim;
	
		DiodeSettings m_diodeSettings;
};

#endif

