Adaptive Real-Time Control of De-Emphasis Level in a USB 3.0 Signal Conditioner Based on Incoming Signal Frequency Range

An apparatus, comprising:

• a differential equalizer having a first differential input and a second differential input;
• an amplifier coupled to a first differential output and a second differential output of the differential equalizer;
• a logical combiner having an output coupled to a control input of the amplifier, wherein the logical combiner receives de-emphasis parameters on a first input;
• a frequency detector coupled to the first and second differential inputs, the frequency detector including
• a) a differential to single signal logic,
• b) a counter coupled to an output of the differential to single transformer,
• c) a clock signal input coupled to the counter,
• d) a comparator that outputs an LFPS_true or LFPS_not-true signal into a second input of the logical combiner;
• an amplifier coupled to the first differential output and the second differential output of the differential equalizer;
• and
• a squelch element having an output coupled to the differential equalizer and the comparison element.

A method, comprising:

• sensing a differential signal;
• applying a differential to single-ended conversion on the differential input to create a single-ended signal;
• counting a number of transitions of the single-ended signal in a time period;
• determining if the count of the number of transitions is higher than a comparison value;
• generating an LPFS_not-true signal if the count of the number of transitions is not higher than a comparison value;
• receiving a de-emphasis parameter;
• and
• blocking a conveyance of the de-emphasize parameter to an amplifier of the differential signal if the LFPS_not-true signal has been generated.