diode equivalent circuits

• an equivalent circuit is a combination of elements properly chosen to best represent the actual characteristics of device in a particular region
• 3 equivalent composition

  1. ideal
  2. constant voltage drop/ simplified
  3. piecewise linear equivalent
• piecewise/linear assumptions


  linear even with small non-linearity
• simplified/constant voltage drop

  1. we have to consider the linear curve instead of a small non-linearity
  2. we will consider the diode resistance RD equal to zero
• piecewise/linear


  Vout=Vin-Vb-IdRd
• simplified/constant voltage drop


  Vout=Vin-Vb
• ideal


  Vin=Vout