Optical time synchronization
AssigneeDENSO International America, Inc.
InventorDaniel Lee
Life of this patent
Estimating the term…
Abstract
A system and method for synchronizing clocks. The system may include a master device having a reference clock and slave devices whose clocks may be synchronized with the reference clock. The master device may drive a light transmitter (e.g., LED) to produce a light pulse with each clock cycle of the reference clock. The light pluses may be distributed by a transmissive medium, such as a low cost optical fiber.
Claims22
A system for generating a clock signal in a device, the system comprising:
- an optical receiver configured to receive light energy corresponding to a reference oscillation signal, the optical receiver operable to generate a receiver output based on the light energy;
- and
- an oscillator configured to generate an oscillating signal, the oscillator being operably coupled to the receiver output of the optical receiver, wherein the oscillating signal of the oscillator is substantially locked to the reference oscillation signal received via the optical receiver,
- wherein the optical receiver and the oscillator are provided in the device, and wherein the device is operable in a low-power mode in which one or more components of the device other than the optical receiver and the oscillator are substantially unpowered, and wherein, in the low-power mode, the oscillating signal of the oscillator is substantially locked to the reference oscillation signal.
A slave device that is remote from a master device, the slave device comprising:
- an optical receiver configured to receive light energy corresponding to a reference oscillation signal generated by the master device, the optical receiver operable to generate a receiver output based on the light energy;
- an oscillator configured to generate an oscillating signal, the oscillator being operably coupled to the receiver output of the optical receiver, wherein the oscillating signal of the oscillator is substantially locked to the reference oscillation signal received via the optical receiver and generated remotely from the optical receiver;
- and
- wherein the slave device is operable in a low-power mode in which one or more components of the device other than the optical receiver and the oscillator are unpowered, and wherein, in the low-power mode, the oscillating signal of the oscillator is substantially locked to the reference oscillation signal.
A method of synchronizing an oscillation signal to a reference oscillation signal that is generated remotely from the oscillation signal, the method comprising:
- receiving, in an optical receiver, light energy corresponding to the reference oscillation signal;
- generating a receiver output based on the light energy;
- substantially locking an oscillator signal of an oscillator to the reference oscillation signal;
- and
- entering a low-power mode in which one or more components of a device other than the optical receiver and the oscillator are substantially unpowered, wherein, in the low-power mode, the oscillator signal of the oscillator is substantially locked to the to the reference oscillation signal.
Dependencies are inferred from the claim text.