Use the Bias Spec design form to view and edit bias parameters.
When creating a design, depending on the selected PI Device family, PI Expert calculates the Voltage values for the bias winding.
To edit the calculated parameter, click the icon 
on the right of the parameter box. The 
icon now indicates that the custom parameter value is entered. Click the icon once again to restore the automatically calculated value.
Bias Voltage Tolerance section displays automatically calculated min and max voltage limits depending on bias voltage value.
You can turn on using Linear Regulator circuit by selecting YES in Use Linear Regulator drop-down box. You can view and change Linear Regulator circuit components on RBIAS circuit Components form.