Initial phase control of an oscillator

An initial phase control for a delay cell, comprising:

• a current source circuit coupled to a first node of the delay cell;
• a current provider;
• and
• an initial phase controller including at least one switch coupled to said current source circuit and to said current provider to set an initial phase of the delay cell output such that the current source circuit and current provider are selectively and synchronously in an on or off state such that when the current source circuit and current provider are in an on state, the current source circuit draws a current through the first node of the delay cell and the current provider provides current through a second node of the delay cell and such that the phase of the delay cell output is started in a predetermined initial phase,
• wherein the initial phase controller includes a set switch, a first reset switch, and a current source coupled to ground, wherein the set switch is coupled between a power supply and the current source and the first reset switch is coupled between the first node and the current source.

A differential ring oscillator with initial phase control and having a plurality of delay cells in a ring configuration, comprising:

• a first delay cell, one or more intermediate delay cells, and a last delay cell, wherein each delay cell is adapted to receive a first input and a second input and wherein each delay cell has a first output node and a second output node, wherein the delay cells are configured in a sequential ring configuration such that the first and second output nodes of the last delay cell are coupled to the second and first inputs of the first delay cell, respectively, and the first and second output nodes of each of the first and intermediate delay cells are coupled to the first and second inputs of a subsequent delay cell comprising the intermediate and the last delay cells, respectively;
• and
• at least one initial phase control circuit, each initial phase control circuit coupled to one of the delay cells, each initial phase control circuit comprising:
• a current source circuit coupled to a first node of the delay cell to which the control circuit is coupled;
• a current provider;
• and
• an initial phase controller including at least one switch coupled to said current source circuit and to said current provider to set an initial phase of said delay cell to which the control circuit is coupled such that the current source circuit and current provider are selectively and synchronously in an on or off state such that when the current source circuit and current provider are in an on state, the current source circuit draws a current through the first node of the delay cell to which the control circuit is coupled and the current provider provides current through a second node of the delay cell to which the control circuit is coupled,
• wherein the initial phase controller includes a reset switch and a transistor, the reset switch is coupled between a power supply and the transistor, the transistor having collector, base, and emitter nodes coupled to said power supply, the reset switch, and the second node of the delay cell to which the control circuit is coupled, respectively.

A differential ring oscillator with initial phase control and having a plurality of delay cells in a ring configuration, comprising:

• a first delay cell, one or more intermediate delay cells, and a last delay cell, wherein each delay cell is adapted to receive a first input and a second input and wherein each delay cell has a first output node and a second output node, wherein the delay cells are configured in a sequential ring configuration such that the first and second output nodes of the last delay cell are coupled to the second and first inputs of the first delay cell, respectively, and the first and second output nodes of each of the first and intermediate delay cells are coupled to the first and second inputs of a subsequent delay cell comprising the intermediate and the last delay cells, respectively;
• and
• at least one initial phase control circuit, each initial phase control circuit coupled to one of the delay cells, each initial phase control circuit comprising:
• a current source circuit coupled to a first node of the delay cell to which the control circuit is coupled;
• a current provider;
• and
• an initial phase controller including at least one switch coupled to said current source circuit and to said current provider to set an initial phase of said delay cell to which the control circuit is coupled such that the current source circuit and current provider are selectively and synchronously in an on or off state such that when the current source circuit and current provider are in an on state, the current source circuit draws a current through the first node of the delay cell to which the control circuit is coupled and the current provider provides current through a second node of the delay cell to which the control circuit is coupled,
• wherein the initial phase controller includes a set switch, a first reset switch, and a current source coupled to ground, wherein the set switch is coupled between a power supply and the current source and the first reset switch is coupled between the first node of the delay cell to which the control circuit is coupled and the current source.