Use this electronics calculation for a first-pass component, converter, signal, motor, or sensor estimate when the stated operating conditions and units match the device data.

Area ratio

Optional number input.

Compute the current mirror output-to-reference ratio from the mirror transistor area ratio, defaulting to 1. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Current mirror ratio (ratio)

The resulting current mirror ratio returned as a number.

• BJT calculations using a fixed current gain or junction drop are operating-point approximations. Gain, Early effect, saturation voltage, leakage, temperature, frequency, bias network loading, and safe operating area vary by device and conditions.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check the result against the current datasheet and worst-case operating corners, then verify the circuit or measurement with simulation and bench testing where failure matters.

• Current Gain Linear

  Compute the linear current gain as the ratio of output to input current.

• Ferrite Core Area Product

  Estimate required ferrite core window-area × cross-section from the Magnetics design form WaAc=Pout·Dcma/(Kt·Bmax·f). Enter circular-mils-per-ampere current-density allowance, gauss, hertz, and the topology constant from the same design method; output is cm⁴.

• Voltage Attenuator Ratio

  Compute the linear voltage attenuation ratio from output over input voltage.