Shockley Diode Calculator
Calculate current-voltage relationships in diodes using the Shockley diode equation
Calculate Diode Characteristics
1 = ideal diode, 1-2 = real diode
Reverse saturation current (temperature dependent)
~26 mV at room temperature (300K)
Voltage across the diode
Diode Characteristics
Shockley Equation: I = Is(eVD/nVT - 1)
Parameters: n=1, Is=0.000e+0 A, VT=0.026V
Calculation: I = 0.000e+0 A × (e0/1×0.026 - 1)
Diode Analysis
Example Calculation
Silicon Diode Forward Bias
Diode Type: Real silicon diode (n = 1.2)
Saturation Current: 1 nA (typical at room temperature)
Thermal Voltage: 26 mV (at 300K/27°C)
Applied Voltage: 0.7V (forward bias)
Calculation
I = Is(eVD/nVT - 1)
I = 1×10⁻⁹ × (e0.7/(1.2×0.026) - 1)
I = 1×10⁻⁹ × (e22.44 - 1)
I ≈ 5.2 mA
This shows the exponential current increase in forward bias
Diode Parameters
Emission Coefficient (n)
1 = Ideal diode
1-2 = Real diode
Accounts for manufacturing imperfections
Saturation Current (Is)
Temperature dependent
Typically nA to pA range
Reverse leakage current
Thermal Voltage (VT)
VT = kT/q
~26 mV at 300K
Proportional to absolute temperature
Bias Conditions
Forward: VD > 0
Reverse: VD < 0
Silicon conducts at ~0.7V forward
Common Diode Types
Diode Tips
Current increases exponentially with forward voltage
Temperature affects saturation current significantly
Reverse bias current is approximately -Is
Use current limiting resistors to prevent damage
Ideal diode model (n=1) is sufficient for most applications
Understanding the Shockley Diode Equation
What is the Shockley Equation?
The Shockley diode equation describes the current-voltage relationship in p-n junction diodes. It models both ideal and real diode behavior by accounting for the exponential relationship between forward voltage and current.
Key Physics Principles
- •Exponential current increase in forward bias
- •Temperature dependence through thermal voltage
- •Emission coefficient accounts for real device effects
- •Saturation current represents reverse leakage
Shockley Diode Equation
I = Is(eVD/nVT - 1)
Current vs. voltage relationship
Parameter Definitions
Note: At room temperature (300K), thermal voltage VT ≈ 26 mV. The equation becomes highly nonlinear for forward voltages above a few tenths of a volt.
Applications & Use Cases
Circuit Analysis
Calculate operating points and I-V characteristics of diode circuits
Device Modeling
Model real diode behavior for accurate circuit simulation
Temperature Analysis
Analyze temperature effects on diode performance