A circuit has a first transistor having a first current electrode coupled to a first supply voltage terminal and a second current electrode coupled to a virtual supply voltage node. A second transistor has a first current electrode coupled to the first supply voltage terminal and a control electrode coupled to the virtual supply voltage node. A first load has an input and has an output coupled to a second current electrode of the second transistor. A third transistor has a control electrode coupled to the output of the first load. A second load has an input coupled to the first supply voltage terminal, and has an output that is coupled to both a control electrode of the first transistor and a first current electrode of the third transistor. The virtual supply voltage node provides an operating voltage to a circuit module that alternates between normal and drowsy operating modes.