Oscillator circuit, device and method for generating an oscillator signal

An oscillator circuit, comprising:

• a current controller, a first capacitor and a second capacitor,
• a current generator coupled to the current controller, the first and the second capacitor, and is operable, under control of a control signal of the current controller, provide charging currents,
• a comparator stage comprising a first input coupled to the first capacitor, a second input coupled to the second capacitor and a reference input to be supplied with the reference voltage, and further comprising an oscillator output to provide a clock signal based on a comparison of the capacitor voltages and the reference voltage, respectively, and
• a modulation circuit comprising an oscillator input to input the clock signal, a reference output is connected to the current generator, and being operable to alternate between the charging currents, such that a charging current is provided as reference current at the reference output and at least one charging current is provided to alternately charge/discharge the first capacitor and the second capacitor to respective capacitor voltages,
• wherein the current generator comprises a current mirror having at least two current sources, each being operable to, under control of the current controller, generate the charging currents, and a switching arrangement alternately connecting the current sources to the first capacitor and to the second capacitor;
• wherein in a dynamic element matching operation switching states of the switching arrangement are alternated depending on the clock signal, and
• wherein the current mirror comprises a third current source being operable to, under control of the current controller, generate a third charging current, the switching arrangement couples the third current source to the first capacitor and to the second capacitor;
• wherein in the dynamic element matching operation switching states of the switching arrangement alternate electrical connections of the first current source, second current source and the third current source such that:
• in the first switching state, the first current source is electrically connected to the first capacitor, the second current source is electrically connected to the second capacitor and the third current source is electrically connected to the reference output,
• in a second switching state, the first current source is electrically connected to the second capacitor, the second current source is electrically connected to the reference output and the third current source is electrically connected to the first capacitor, and
• in a third switching state, the first current source is electrically connected to the reference output, the second current source is electrically connected to the first capacitor and the third current source is electrically connected to the second capacitor.