Oscillator circuit

An oscillator circuit comprising:

• first, second, and third capacitors, each having two terminals and having a voltage between the two terminals;
• a plurality of first current sources, wherein each of the first current sources charges an associated one of the capacitors;
• a plurality of second current sources, wherein each of the second current sources discharges an associated one of the capacitors;
• a plurality of switches, wherein each of the switches is connected between an associated one of the first current sources and an associated one of the second current sources;
• a first charge/discharge switching circuit connected to the first capacitor for generating a first switching signal that shifts the first capacitor between a charging state and a discharging state;
• a second charge/discharge switching circuit connected to the first and second capacitors for generating a second switching signal that shifts the second capacitor between a charging state and a discharging state;
• and
• a third charge/discharge switching circuit connected to the first and third capacitors for generating a third switching signal that shifts the third capacitor between a charging state and a discharging state, the first to third switching signals of the charge/discharge switching circuits having different phases;
• wherein each of the first to third charge/discharge switching circuit receives a first capacitor voltage between the terminals of the first capacitor and compares the first capacitor voltage with a first reference voltage and a second reference voltage to generate the corresponding switching signal that has a predetermined phase, a triangular wave signal is generated at one of the two terminals of each of the capacitors, and wherein the triangular wave signals have different phases.

An oscillator circuit for generating a plurality of triangular shape signals having different phases, the oscillator circuit comprising:

• a plurality of capacitors having output nodes;
• a plurality of first current sources, each charging the corresponding capacitor via a corresponding one of the output nodes;
• a plurality of second current sources each having current supply capacity larger than that of each of the first current sources, each of the second current sources discharging the corresponding capacitor via a corresponding one of the output nodes;
• a plurality of switching control circuits coupled to one of the output nodes in common and generating switching signals having different phases;
• and
• a plurality of switches, each coupled between a corresponding one of the output nodes and a corresponding one of the second current sources, wherein each switch is controlled in response to a corresponding one of the switching signals.