Delivering a fine delay stage for a delay locked loop
AssigneeSiemens Aktiengesellschaft
InventorsRajashekhar Rao, Patrick Heyne
Life of this patent
Estimating the term…
Abstract
A circuit, for use in a delay locked loop, provides a phase-shifted output relative to a first signal. The circuit includes plural current sources, current source switches that are selectable to transmit varying amounts of current from the plural current sources, and input switches that receive current via the current source switches and provide the phase-shifted output. The output switches include a first switch for receiving the first signal and a second switch for receiving a second signal phase-shifted from the first signal. The phase-shifted output relative to the first signal is based on an amount of current that passes through each input switch.
Claims22
A circuit, for use in a delay locked loop, which provides a phase-shifted output relative to a first signal, the circuit comprising:
- plural current sources;
- current source switches that are selectable to transmit varying amounts of current from the plural current sources;
- and
- input switches that receive current via the current source switches and provide the phase-shifted output, the input switches comprising a first input switch receiving the first signal and a second input switch receiving a second signal phase-shifted from the first signal;
- wherein the phase-shifted output is based on an amount of current that passes through each of the input switches.
A method for providing a phase-shifted output relative to a first signal in a delay locked loop, comprising:
- selecting varying amounts of current from plural current sources by enabling current source switches;
- and
- transmitting a first signal to a first input switch and a second signal phase-shifted from the first signal to a second input switch;
- wherein the phase-shifted output relative to a first signal is based on an amount of current that passes through the first input switch and the second input switch.
Dependencies are inferred from the claim text.