| US 7,613,266 B1 | ||
| Binary controlled phase selector with output duty cycle correction | ||
| Gerald Robert Talbot, Concord, Mass. (US) | ||
| Assigned to Advanced Micro Devices, Inc., Sunnyvale, Calif. (US) | ||
| Filed on Jan. 13, 2005, as Appl. No. 11/33,641. | ||
| This patent is subject to a terminal disclaimer. | ||
| Int. Cl. H04L 7/00 (2006.01) | ||
| U.S. Cl. 375—371 [375/226; 375/362; 327/144; 327/141; 327/147; 327/151] | 20 Claims |

| 1. A phase selection circuit comprising:
a selection circuit configured for receiving a first prescribed number of phase signals representing respective equally-spaced
phases of a clock signal, the selection circuit configured for selecting and outputting, from the first prescribed number
of phase signals, first and second adjacent phase signals based on a phase selection value representing one of a second prescribed
number of phases, the second prescribed number a multiple of the first prescribed number, the selection circuit further configured
for outputting a digital interpolation control value based on the phase selection value relative to the first and second adjacent
phase signals;
first and second binary weighted current sources configured for outputting first and second contribution currents onto a summing
node based on the first and second adjacent phase signals, respectively, and based on the digital interpolation control value,
the first and second contribution currents forming at the summing node an interpolated signal that is interpolated relative
to the first and second adjacent phase signals and the digital interpolation control value; and
an amplifier circuit configured for outputting the interpolated signal as a phase-interpolated clock signal, having a voltage
swing between a first reference voltage and a second reference voltage, according to the phase selection value.
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