Method and apparatus of a self-biased RC oscillator and ramp generator

A self-biased RC (resistor-capacitor) oscillator and ramp generator circuit, comprising:

• a combined current and voltage reference circuit for providing a reference current, a first reference voltage, and a second reference voltage, the combined current and voltage reference circuit including a circuit branch having a first NMOS transistor, a first PMOS transistor, and a resistor coupled in series;
• and
• a signal generating circuit including a capacitor, the signal generating circuit being configured to charge and discharge the capacitor between the first reference voltage and the second reference voltage by using a comparator circuit to compare a capacitor voltage with the first reference voltage and the second reference voltage.

A self-biased RC (resistor-capacitor) oscillator and ramp generator circuit, comprising:

• a combined current and voltage reference circuit for providing a reference current, a first reference voltage, and a second reference voltage, the combined current and voltage reference circuit including a circuit branch having a first NMOS transistor, a first PMOS transistor, and a resistor coupled in series, and a temperature compensation circuit in parallel with the resistor;
• and
• a signal generating circuit including a capacitor, the signal generating circuit being configured to charge and discharge the capacitor between the first reference voltage and the second reference voltage.