Automated tuning in wide range multi-band VCO with internal reset concept
First Claim
1. A structure for use with a voltage controlled oscillator (VCO) having a plurality of frequency bands, the structure comprising:
- a jump-up structure and a jump-down structure;
each jump-up and jump-down structure further comprising;
an analog control signal to adjust a frequency value or a delay value within each frequency band;
a plurality of digital control signals representing the analog control signal of a current band;
a feedback loop to control an analog tuning control circuit;
a monitor structure to detect a switching point for switching to an alternate band;
a reset generating structure to issue one or more reset signals for suspending the operation of the VCO when the switching point is detected;
a plurality of initializing structures to raise or lower the analog control signal to a value in a predetermined range;
a band select structure which uses the reset signals to change the digital control signals to switch to the alternate band;
a plurality of reset release structures to release the reset signals from the VCO to resume operation after switching to the alternate band when the analog control signal is equal to the value in the predetermined range; and
a switch structure to couple at least one of the initializing structures to the analog control signal when the reset signal is issued, and to decouple at least one of the initializing structures from the analog control signal when the reset signal is released;
wherein the jump-up and the jump-down structures detect when the analog control signal has reached a predetermined operational limit in the current band, and generate the reset signals to switch to the alternate band based on a direction of analog control signal movement, and setting a new value for the analog control signal to a predetermined operational limit for the alternate band after the VCO is released to functional mode.
6 Assignments
0 Petitions
Accused Products
Abstract
Circuits and methods for automated real-time tuning of wide range frequency/delay voltage controlled oscillators (VCO) using a reset mechanism, to account for run-time variations such as power supply, temperature, reference clock frequency and input slew drift etc is described. It finds extensive applications in wide range, multi frequency band phase and delay locked loops. In one embodiment, an automated Jump-Down band switching structure and method for use in VCOs with a plurality of frequency bands is described. This involves monitoring the VCO'"'"'s analog control voltage signal until it reaches a predetermined lower limit, at which time band switching to an overlapping lower frequency band is triggered by an internally generated reset signal, while simultaneously charging the analog control voltage to a limit in a pre-determined range of the lower band, to avoid phase detector malfunctions in the PLL/DLL system at lower control voltages during band switch.
-
Citations
16 Claims
-
1. A structure for use with a voltage controlled oscillator (VCO) having a plurality of frequency bands, the structure comprising:
-
a jump-up structure and a jump-down structure; each jump-up and jump-down structure further comprising; an analog control signal to adjust a frequency value or a delay value within each frequency band; a plurality of digital control signals representing the analog control signal of a current band; a feedback loop to control an analog tuning control circuit; a monitor structure to detect a switching point for switching to an alternate band; a reset generating structure to issue one or more reset signals for suspending the operation of the VCO when the switching point is detected; a plurality of initializing structures to raise or lower the analog control signal to a value in a predetermined range; a band select structure which uses the reset signals to change the digital control signals to switch to the alternate band; a plurality of reset release structures to release the reset signals from the VCO to resume operation after switching to the alternate band when the analog control signal is equal to the value in the predetermined range; and a switch structure to couple at least one of the initializing structures to the analog control signal when the reset signal is issued, and to decouple at least one of the initializing structures from the analog control signal when the reset signal is released; wherein the jump-up and the jump-down structures detect when the analog control signal has reached a predetermined operational limit in the current band, and generate the reset signals to switch to the alternate band based on a direction of analog control signal movement, and setting a new value for the analog control signal to a predetermined operational limit for the alternate band after the VCO is released to functional mode. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A method of switching between frequency bands on a voltage controlled oscillator (VCO) the steps comprising:
-
providing a jump-up structure and a jump-down structure; providing an analog control signal; providing a feedback loop to control an analog tuning control circuit; providing a plurality of digital control signals representing the analog control signal of a current band; adjusting a frequency value or a delay value within each frequency band of the VCO; providing a monitor structure; comparing an analog tuning control signal to a predetermined limit; detecting a switching point for switching to an alternate band; providing a reset generating structure; issuing one or more reset signals for suspending the operation of the VCO when the switching point is detected; providing a plurality of initializing structures for raising or lowering the analog control signal to a value in a predetermined range; setting an analog control voltage to a value in a predetermined range; providing a band select structure for changing the digital control signals to switch to the alternate band; providing a plurality of reset release structures to release the reset signals from the VCO to resume operation after switching to the alternate band when the analog control signal is equal to the value in the predetermined range; providing a switch structure to couple at least one of the initializing structures to the analog control signal when the reset signal is issued, and to decouple at least one of the initializing structures from the analog control signal when the reset signal is released; issuing a reset signal to suspend the operation of the VCO when the analog tuning control signal is equal to the predetermined limit; assigning a new starting value for the analog tuning control signal; changing the digital tuning controls to the next alternate frequency band; and releasing the VCO to functional mode. - View Dependent Claims (13, 14, 15, 16)
-
Specification