Use this semiconductor calculation for first-order device, material, fabrication, interconnect, packaging, or reliability estimates when every coefficient and unit convention is known.

Lambda (V^-1)

Required number in V^-1.

ID (mA)

Required number in mA. Quiescent drain current.

The cited overview of MOSFET supplies background for the terminology and domain context used by this tool.^[1]

Compute the MOSFET small-signal output resistance from channel-length modulation. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.

ro (kΩ)

Returned number in kΩ.

• Material composition, geometry, process history, temperature, electric field, bias, interfaces, parasitics, and fitted parameter ranges can invalidate a compact semiconductor model.
• Lambda must be at least 5e-324.
• ID must be at least 5e-324.
• Use finite inputs in the displayed units, preserve source measurements and assumptions, and independently verify consequential decisions.

Compare the estimate with measured process data, current device documentation, and a higher-fidelity circuit, field, thermal, quantum, or TCAD model when the decision requires it.

• MOSFET Channel-Length Modulation Calculator

  Compute the channel-length modulation parameter from the Early voltage.

• BJT Early Voltage Calculator

  Compute the BJT Early voltage as collector current divided by small-signal output conductance, VA = IC / go. IC is quiescent collector current in mA and go is dIC/dVCE in S.

• BJT Output Conductance Calculator

  Compute the BJT small-signal output conductance as collector current divided by Early voltage, go = IC / VA. IC is quiescent collector current in mA and VA is Early voltage in V.