A regulator circuit for reducing the output noise when regulators are
switched includes a linear regulator and a switching regulator. The
linear regulator generates a first regulator voltage from an input
voltage with a first feedback loop. The switching regulator generates a
second regulator voltage from the input voltage with a second feedback
loop, which is connected to the first feedback loop. A loop control
circuit controls the first feedback loop so as to lower the first
regulator voltage when the switching regulator is activated.