Clock-data recovery and method for binary signaling using low resolution ADC

A clock-data recovery (CDR) circuit comprising:

• a variable-gain amplifier (VGA) to amplify an input signal with a gain factor controlled by a gain setting to generate an amplified signal;
• an analog-digital converter to convert the amplified signal into a converter output in accordance with a timing provided by a recovered clock, wherein the converter output has N levels;
• a timing detection circuit to generate a timing error signal based on the converter output;
• a filter to filter the timing error signal to generate a control signal;
• a controllable oscillator to generate the recovered clock under a control of the control signal;
• an automatic gain control (AGC) to set the gain setting to control the gain factor of the VGA based on the converter output;
• and
• a data recovery circuit for generate a recovered data based on the converter output, wherein the data recovery circuit comprises at least a delay circuit and a mapping table, wherein the mapping table is established in accordance with characteristics of an inter-symbol interference within the binary signal.

A clock-data recovery method applied to a clock-data recovery circuit, the method comprising:

• amplifying an input signal with a gain factor controlled by a gain setting to generate an amplified signal;
• quantizing the amplified signal into a converter output in accordance with a timing provided by a recovered clock, wherein the converter output has N levels;
• generating a timing error signal the converter output;
• filtering the timing error signal to generate a control signal;
• controlling a timing of the recovered clock in accordance with the control signal;
• controlling the gain setting based on the converter output;
• and
• generating a recovered data based on the converter output, wherein the step of generating the recovered data further comprising:
• using at least a delay function to generate a previous value of the converter output, and
• using a mapping function to map a plurality of inputs, including at least the converter output and the previous value of the converter output, into the recovered data.