Coolquest, Inc.	Home	Products	Support	About	Contact
C++BOLD Example Design: IROD

// THIS FILE IS IN THE PUBLIC DOMAIN.
// IT IS PROVIDED AS IS WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT
// NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 
#ifndef _LV_ComparatorH_
#define _LV_ComparatorH_
 
#include "ad1580.h"
 
// Low-Voltage comparator
 
// The user sets the overvoltage threshold by changing the value of RAdjust via a call to SetTypeName().
// RAdjust's value is RAdjust = Rh/( Vthresh/Vref - 1 ) where:
//   Rh      = 10.2  kohm
//   Vref    = 1.225/2 V  (.6125V)
//   Vthresh = user's desired threshold voltage--must be greater than Vref.
 
// See LV_ComparatorResistorValues.xls for a table of RAdjust values.
 
 
class CM_LV_Comparator : public TModule {
public:
  port VCC;    // 3.3V supply
  port GND;
  port IN;
  port OUT;    // 3.3V if IN > threshold, 0V if IN < threshold
 
  CP_AD1580    Reference;  // 1.225V voltage reference
  CP_R4_7K     Rb;         // bias resistor for reference
  CP_R10_2KP1  Rrefh;      // Rrefh and Rrefl divide reference voltage by two
  CP_R10_2KP1  Rrefl;
  CP_R10_2KP1  Rh;         // half of resistor divider, tied to IN
  CP_RCHIP805  RAdjust;    // other half of resistor divider (also known as Rl) -- user must specify actual value using SetTypeName()
  CP_AD8517ART Amp;        // low-voltage rail-to-rail op-amp
 
public:
  virtual void Register() {
    reg( VCC );
    reg( GND );
    reg( IN  );
    reg( OUT );
 
    reg( Reference );
    reg( Rb );
    reg( Rrefh );
    reg( Rrefl );
    reg( Rh );
    reg( RAdjust );
    reg( Amp );
  }
 
  virtual void Connect() {
    VCC   << Amp.VPP;                      // power
    GND   << Amp.VNN << Reference.VNN;
    OUT   << Amp.OUT;
 
    "/NC"   << Reference.NC;
    "V_REF" << Reference.VPP ^ Rb ^ VCC;                    // reference is biased by Rb
    "V_REF" ^ Rrefh ^ "IN_N" << Amp.IN_N ^ Rrefl   ^ GND;   // V_REF/2    goes to Amp - input
    IN      ^ Rh    ^ "IN_P" << Amp.IN_P ^ RAdjust ^ GND;   // divided IN goes to Amp + input
  }
};
 
#endif