A microelectromechanical sensor device, comprising a detection structure and an associated electronic circuitry; wherein said electronic circuitry is configured to receive, when said microelectromechanical sensor device is powered, an external power supply voltage (V DD) and comprises a voltage regulator configured to generate a regulated voltage (V REG) having a value different from said external power supply voltage (V DD) and at least one voltage domain powered by said regulated voltage (V REG), characterized in that said voltage domain comprises a switching control logic and a number of sub-domains, distinct from each other and selectively controllable in power-on or power-off by said switching control logic; and in that said electronic circuitry comprises a power supply management core, always powered by said external power supply voltage (V DD) and configured to control said voltage regulator to selectively interrupt the power supply of said voltage domain to implement: a first power-down condition of said microelectromechanical sensor device wherein said voltage regulator is disabled; and a second power-down condition of said microelectromechanical sensor device wherein said voltage regulator is enabled to power said voltage domain through said regulated voltage (V REG) and said switching control logic is configured to interrupt power supply of one or more of said sub-domains to reduce a power consumption of said microelectromechanical sensor device, said first and second power-down conditions being associated with absence of data acquisition by said microelectromechanical sensor device, wherein said power supply management core is configured to automatically alternatively enable said first or said second power-down condition upon a first power-on of said microelectromechanical sensor device, as a function of a configuration signal (S conf). characterized in that said voltage domain comprises a switching control logic and a number of sub-domains, distinct from each other and selectively controllable in power-on or power-off by said switching control logic; and in that said electronic circuitry comprises a power supply management core, always powered by said external power supply voltage (V DD) and configured to control said voltage regulator to selectively interrupt the power supply of said voltage domain to implement: a first power-down condition of said microelectromechanical sensor device wherein said voltage regulator is disabled; and a second power-down condition of said microelectromechanical sensor device wherein said voltage regulator is enabled to power said voltage domain through said regulated voltage (V REG) and said switching control logic is configured to interrupt power supply of one or more of said sub-domains to reduce a power consumption of said microelectromechanical sensor device, said first and second power-down conditions being associated with absence of data acquisition by said microelectromechanical sensor device, wherein said power supply management core is configured to automatically alternatively enable said first or said second power-down condition upon a first power-on of said microelectromechanical sensor device, as a function of a configuration signal (S conf).