A/D converter, method for adjusting analog signal therein, and method for converting analog signal into digital signal

A method for adjusting an analog input signal in an analog-to-digital converter (ADC), the method comprising the steps of:

• sampling the analog input signal;
• generating a digital value comprising most significant bits corresponding to the sampled analog input signal;
• determining if amounts of bits 0 and 1 of the most significant bits being the same;
• and
• modifying offsets of the analog input signal with respect to a reference value when the amounts of bit 0 and 1 of the most significant bits being not the same.

A method for adjusting an analog input signal in an analog-to-digital converter (ADC), the ADC comprising a plurality of stages of ADC units, the method comprising the steps of:

• using a sample-and-hold amplifier (SHA) to sample the analog input signal;
• a first stage of the ADC units generating a digital value comprising most significant bits corresponding to the sampled analog input signal;
• determining if amounts of bits 0 and 1 of the most significant bits being the same;
• and
• controlling the SHA to modify offsets of the analog input signal with respect to a reference value when the amounts of bit 0 and 1 of the most significant bits being not the same.

A method for converting an analog input signal into a digital signal by an analog-to-digital converter (ADC), the ADC comprising a plurality of stages of analog-to-digital converting units, the method comprising the steps of:

• generating digital values corresponding to the analog input signal, wherein one of the digital values comprising most significant bits;
• modifying offsets of the analog input signal with respect to a reference value according to the most significant bits;
• detecting if values of a residue signal, generated by one of the analog-to-digital converting units, being over an operating range of the analog-to-digital converting units;
• outputting a determining signal according to the over-range detection;
• adjusting an input gain for the analog input signal according to the determining signal;
• generating new digital values corresponding to the modified and adjusted analog input signal;
• and
• converting the new digital values into the digital signal.