Regulator circuit, method, and corresponding power supply system

A system comprising:

• a main supply line configured to carry a supply voltage having a first voltage value;
• an ancillary supply line configured to carry a supply voltage having the first voltage value;
• a reference supply line;
• an input terminal coupled to the main supply line;
• an output stage with an output terminal, the output stage coupled between the main supply line and the reference supply line;
• an error amplifier having a supply terminal coupled to the ancillary supply line, a first input coupled to the input terminal, a second input, and an output coupled to drive the output stage;
• a feedback resistor coupled between the output terminal and the second input of the error amplifier for transferring to a feedback signal indicative of an output signal at the output terminal to the error amplifier;
• and
• a current generator coupled to the feedback resistor and also coupled between the input terminal and the main supply line, the current generator configured to generate a soft-start current at a node between the second input of the error amplifier and the feedback resistor, an intensity of the soft-start current ramping down to zero.

A method of providing soft-start operation in a track regulator circuit, the method comprising:

• receiving an input signal at an input terminal of the track regulator circuit;
• applying an output signal to a load via an output terminal of an output stage of the track regulator circuit;
• transferring a feedback signal indicative of the output signal to an error amplifier via a feedback resistor, the error amplifier driving the output stage as a function of a difference between the input signal and the output signal so that the output signal tracks the input signal;
• and
• generating a soft-start current to flow to unbalance the error amplifier, the soft-start current having an intensity that ramps down to zero.