Analog-to-digital conversion device

An analog-to-digital conversion device, comprising:

• a sensing circuit, coupled to a bit line of a memory array, and used to sense a current in the bit line to generate a bit-sequence, the bit-sequence has a form of a thermometer code to represent an analog value, comprising:
• a sensing amplifier, having an input end coupled to the bit line, the input end has a first node, and the first node has a first node voltage,
• wherein, the sensing circuit generates the bit-sequence according to the first node voltage and a threshold voltage of the sensing amplifier,
• a latch logic circuit, including a plurality of latches and a plurality of logic circuits to form a page buffer of the memory array, and used to generate a bit-set according to the bit-sequence, the bit-set has a form of a binary code to represent a digital value;
• and
• at least one latch element, coupled to the sensing circuit, and used to set an initial charge amount of the first node,
• wherein, the latches and the logic circuits perform a conversion process to convert the bit-sequence into the bit-set, and the conversion process has a bit width.