Oscillator Device

An oscillator device comprising:

• a ring oscillator circuit with at least one delay stage with an output of a last delay stage fed back to an input of a first delay stage, wherein each of the delay stages is configured to receive a charging current and to provide a delay that is dependent on the charging current and at least one of the delay stages comprises a metal-oxide-semiconductor field-effect transistor;
• and
• a bias circuit comprising an output terminal coupled to an input terminal of the ring oscillator circuit, wherein the bias circuit is configured to receive a temperature-independent reference voltage and comprises a current source with a main NMOS-transistor, the current source being configured to provide a control current to the ring oscillator circuit which is proportional to a difference of the temperature-independent reference voltage and a gate-source voltage of the main NMOS-transistor, wherein a gate-source voltage of the main NMOS-transistor comprises a negative temperature coefficient, wherein the bias circuit further comprises a differential amplifier configured to compare the temperature-independent reference voltage with a measurement voltage, a feedback transistor with a gate-drain path of the feedback transistor being arranged in a negative feedback loop of the differential amplifier, a resistor network, and wherein a drain of the feedback transistor is coupled to a first terminal of the resistor network and a drain of the main NMOS-transistor is coupled to a second terminal of the resistor network and the measurement voltage is tapped at the first terminal of the resistor network.