Solid-state imaging device, semiconductor integrated circuit, and signal processing method

A semiconductor integrated circuit, comprising:

• a plurality of pixel circuits arranged in a matrix, each of which performs photoelectric conversion on a received light;
• and
• an AD conversion unit configured to convert a signal voltage into a digital signal represented as a plurality of bits, the signal voltage being a resultant of the photoelectric conversion,
• wherein said AD conversion unit includes:
• a reference voltage generation unit configured to generate a plurality of reference voltages within a possible range for the signal voltage, each of the reference voltages being different from each other;
• a most significant bit conversion unit configured to identify, from among a plurality of voltage sections, a voltage section that includes the signal voltage, and to determine a result of the identification as a value of a most significant bit of the digital signal, each of the voltage sections having a corresponding one of the reference voltages as a base point;
• and
• a least significant bit conversion unit configured to convert a difference voltage into a least significant bit of the digital signal, the difference voltage indicating a difference between the signal voltage and the reference voltage that is the base point of the identified voltage section.

A signal processing method used in a solid-state imaging device, said method comprising:

• performing photoelectric conversion on a received light;
• and
• converting a signal voltage into a digital signal represented as a plurality of bits, the signal voltage being a resultant of the photoelectric conversion,
• wherein said converting includes:
• generating a plurality of reference voltages within a possible range for the signal voltage, each of the reference voltages being different from each other;
• identifying a voltage section that includes the signal voltage from among a plurality of voltage sections, and determining a result of the identification as a value of a most significant bit of the digital signal, each of the voltage sections having a corresponding one of the reference voltages as a base point;
• and
• converting a difference voltage into a least significant bit of the digital signal, the difference voltage indicating a difference between the signal voltage and the reference voltage that is the base point of the identified voltage section.