Using high frequency crystal from external module to trim real time clock
AssigneeMedtronic, Inc.
InventorMelvin P. Roberts
Life of this patent
Estimating the term…
Abstract
Techniques including methods and apparatus for calibrating a local clock are provided in an implantable medical device. The implantable medical device includes a telemetry module for receiving a remote signal transmitted by an external device. The received signal is provided to a clocking circuit having a clocking circuit for computation of a calibration factor based on a difference between phases of the clock signal generated by the local clock and transitions in the received remote signal. The calibration factor may be derived as a function of an edge of the clock signal lagging or leading relative to a corresponding edge of the remote signal.
Claims20
A medical system, comprising:
- an external device having a signal generator for generating a remote signal;
- and
- an implantable medical device, including:
- a first input for receiving the remote signal;
- a local clock generator configured to generate a first clock signal;
- a clocking circuit coupled to the first input and the local clock, wherein the clocking circuit is configured to generate a calibration factor for calibrating the first clock signal relative to the remote signal based on an alignment comparison of a cycle edge of the remote signal relative to a cycle edge of the first clock signal.
A method for calibrating a local clock of an implantable medical device, comprising:
- receiving a remote signal communicated from an external device;
- activating a clocking circuit in response to receiving the remote signal;
- and
- initiating a calibration routine, wherein the remote signal is compared to the first clock signal to generate a calibration factor for calibrating the first clock signal relative to the remote signal based on the remote signal and the first clock signal.
Dependencies are inferred from the claim text.