Self-regulating voltage controlled oscillator
The present invention relates to the improvement of a phase noise characteristics of supply voltage in VCO. The delay in delay cells may be controlled to use the resistor of a transmission gate instead of a tail current. That is, the delay of cells is controlled by applying the overdrive voltage in transmission gate. And the self-regulating may be possible to composing a feedback inside the delay cells.
1. A self-regulating voltage controlled oscillator using second type transistor which has first, second and third terminals, wherein current flowing from said first terminal to said second terminal is in proportion to voltage between the first and third terminals, comprising:
(a) first and second transistors of the second type, wherein the first terminals are connected to each other;
(b) first and second transmission gate, each having an input, first and second control, and output terminals, respectively, wherein each of the input terminals is connected to each of the second terminals of said first and second transistors, respectively, and each of the second control and input terminals of the first transmission gate is connected to each of the input and second terminals of the second transmission gate; and
(c) a latch having first and second output terminals, each of which is connected to each of output terminals of said first and second transmission gates, respectively, and first and second input terminals.
2. A self-regulating voltage controlled oscillator of claim 1 further using first type transistor which has first second and third terminals, wherein current flowing from the second terminal to the first terminal is in proportion to voltage between the second and third terminals,
wherein each of said first and second transmission gates comprises first and second type transistors, the first terminal of the first type transistor and the second terminal of the second type transistor is connected to each other to form the input terminal of the transmission gates, the second terminal of the first type transistor and the first terminal of the second type transistor is connected to each other to form the output terminal of the transmission gates, the third terminal of the first type transistor forms the first control terminal, and the third terminal of the second type transistor forms the second control terminal.
3. A self-regulating voltage controlled oscillator of claim 1 , wherein said latch comprises:
first and second transistors of the first type which are connected to each other in parallel, such that, the first terminals of the first and second transistors are connected to each other to form the first output terminal, the second terminals of the first and second transistors are connected to each other, and the third terminal of the first transistor forms the first control terminal of said latch,
third and fourth transistors of the first type which are connected to each other in parallel, such that, the first terminals of the third and fourth transistors are connected to each other to form the second output terminal, the second terminals of the third and fourth transistors are connected to each other, and the third terminal of the fourth transistor forms the second control terminal of said latch, and the third terminal of the second transistor is connected to the connection of the first terminal of the third and fourth transistors, and the third terminal of the third transistor is connected to the connection of the first terminals of the first and second transistors.