Phase locked loop (PLL) with multi-phase time-to-digital converter (TDC)
First Claim
1. A multi-phase time-to-digital converter (TDC) for a phase locked loop (PLL), comprising:
- a first phase finder configured to generate a first fractional phase signal of a multi-phase variable clock (CKV) signal based on at least one of the multi-phase CKV signal or a reference frequency (FREF) signal, the multi-phase CKV signal associated with one or more clock signals and one or more corresponding phases;
a phase predictor configured to generate at least one of;
a phase select (QSEL) signal associated with a fractional frequency command word (FCW) signal based on at least one of a FCW signal or a phase reference (PHR) signal;
ora multi-phase CKV select (CKVSEL) signal corresponding to a clock signal of the one or more clock signals and a phase of the one or more corresponding phases based on at least one of the multi-phase CKV signal or the QSEL signal;
a second phase finder configured to generate a second fractional phase signal of the multi-phase CKV signal based on at least one of the CKVSEL signal or the QSEL signal; and
a phase switch configured to select at least one of the first fractional phase signal or the second fractional phase signal based on a phase error (PHE) signal.
1 Assignment
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Accused Products
Abstract
One or more techniques or systems for locking a phase locked loop (PLL) are provided herein. In some embodiments, a multi-phase time-to-digital converter (TDC) includes a first phase finder, a phase predictor, a second phase finder, and a phase switch. For example, the first phase finder is configured to generate a first fractional phase signal based on a multi-phase variable clock (CKV) signal. For example, the phase predictor is configured to generate a phase select (QSEL) signal or a multi-phase CKV select (CKVSEL) signal based on a frequency command word (FCW) signal or the multi-phase CKV signal. For example, the second phase finder is configured to generate a second fractional phase signal based on the CKVSEL signal or the QSEL signal. For example, the phase switch is configured to select the first or second fractional phase signal based on a phase error (PHE) signal.
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Citations
20 Claims
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1. A multi-phase time-to-digital converter (TDC) for a phase locked loop (PLL), comprising:
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a first phase finder configured to generate a first fractional phase signal of a multi-phase variable clock (CKV) signal based on at least one of the multi-phase CKV signal or a reference frequency (FREF) signal, the multi-phase CKV signal associated with one or more clock signals and one or more corresponding phases; a phase predictor configured to generate at least one of; a phase select (QSEL) signal associated with a fractional frequency command word (FCW) signal based on at least one of a FCW signal or a phase reference (PHR) signal;
ora multi-phase CKV select (CKVSEL) signal corresponding to a clock signal of the one or more clock signals and a phase of the one or more corresponding phases based on at least one of the multi-phase CKV signal or the QSEL signal; a second phase finder configured to generate a second fractional phase signal of the multi-phase CKV signal based on at least one of the CKVSEL signal or the QSEL signal; and a phase switch configured to select at least one of the first fractional phase signal or the second fractional phase signal based on a phase error (PHE) signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A phase locked loop (PLL), comprising:
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an accumulator component; an adder component connected to the accumulator component; a loop filter connected to the adder component; a digitally controlled oscillator (DCO) connected to the loop filter; a sigma delta modulation component connected to at least one of the DCO or the loop filter; a counter component connected to at least one of the DCO or the adder component; and a multi-phase time-to-digital converter (TDC), comprising; a first phase finder connected to the DCO; a phase predictor connected to the DCO; a second phase finder connected to the phase predictor; and a phase switch connected to at least one of the first phase finder, the second phase finder, or the adder component. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19)
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20. A method for locking a phase locked loop (PLL), comprising:
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generating a first fractional phase signal of a multi-phase variable clock (CKV) signal based on at least one of the multi-phase CKV signal or a reference frequency (FREF) signal, the multi-phase CKV signal associated with one or more clock signals and one or more corresponding phases; generating a second fractional phase signal of the multi-phase CKV signal based on at least one of the multi-phase CKV signal, a frequency command word (FCW) signal, or a phase reference (PHR) signal; and selecting at least one of the first fractional phase signal or the second fractional phase signal based on a phase error (PHE) signal.
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Specification