Patent ID: 7515083

Claim:
An analog-to-digital converting system, converting an analog input signal into a digital output signal, the analog-to-digital converting system comprising: a track and hold circuit for tracking the input signal during a track mode and holding the tracked input signal during a hold mode; a coarse analog-to-digital converter for converting an output signal of the track and hold circuit into a first digital code according to a first reference voltage, wherein the first digital code is related to a most-significant-bit set of the digital output signal of the analog-to-digital converting system; an encoding and registering unit for storing the first digital code and a second digital code, wherein the second digital code is related to a least-significant-bit set of the digital output signal of the analog-to-digital converting system and the encoding and registering unit encodes the first digital code into a third digital code; a reference voltage generator for generating the first reference voltage provided to the coarse analog-to-digital converter, wherein the reference voltage generator further generates a second reference voltage according to the third digital code encoded by the encoding and registering unit; and a successive approximation analog-to-digital converter, for receiving the output signal of the track and hold circuit, wherein the successive approximation analog-to-digital converter uses a successive approximation algorithm to convert the output signal of the track and hold circuit into the second digital code according to the second reference voltage.