Mixed domain spread spectrum clocking for use in imaging systems for maximum imaging quality and optimized EMI performance
AssigneeNational Semiconductor Corporation
InventorsMatthew Courcy, David Barkin, James Brinkhurst
Life of this patent
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Abstract
A method of operating a line imaging device including receiving a first clock signal indicative of a system timing signal in the line imaging device, generating a second clock signal based on the first clock signal and being unmodulated where the second clock signal being used for driving the imager timing, data sampling and digitizing operations of the line imaging device, and generating a third clock signal based on the first clock signal and being modulated using a spreading waveform where the third clock signal being a spread spectrum clock signal and being used to drive the data transfer operation of the line imaging device.
Claims11
A method of operating a line imaging device comprising:
- receiving a first clock signal indicative of a system timing signal in the line imaging device;
- generating a second clock signal based on the first clock signal and being unmodulated, the second clock signal being used for driving the imager timing, data sampling and digitizing operations of the line imaging device;
- and
- generating a third clock signal based on the first clock signal and being modulated using a spreading waveform, the third clock signal being a spread spectrum clock signal and being used to drive the data transfer operation of the line imaging device.
An analog front end circuit (220) for a line imaging device comprising:
- a first clock generator (210) receiving a first clock signal and generating a second clock signal being unmodulated for driving the imaging, data sampling and digitizing operations of the line imaging device;
- and
- a second clock generator (214) receiving the first clock signal and generating a third clock signal being modulated using a spreading waveform, the third clock signal being a spread spectrum clock signal and being used to drive the data transfer operation of the line imaging device.
Dependencies are inferred from the claim text.