Track and hold amplifiers and analog to digital converters

An analog to digital converter for converting an input signal to an output signal, comprising:

• a track and hold amplifier receiving the input signal to generate a sampled signal, and comprising:
• an input node receiving the input signal;
• a buffer coupled between a first node and an output node;
• a first switch coupled between the input node and the first node;
• a plurality of switching circuits, each comprising:
• a capacitor coupled between the first node and a second node;
• a second switch coupled between the second node and a common node;
• and
• a third switch coupled to the second node, wherein the second switch is turned on and the third switch is turned off when the first switch is turned on, and the first switch and the second switch are turned off when the third switch is turned on;
• and
• a voltage generating unit coupled to the third switch of each of the switching circuits, selectively providing a common signal and a reference signal to the third switches of the switching circuits, wherein the reference signal is independent from the analog signal and the common signal;
• a quantizer quantizing the sampled signal to generate a quantized signal;
• and
• a calibration processor calibrating the quantized signal to generate the output signal.

A track and hold amplifier, comprising:

• an input node receiving an analog signal;
• an amplifier having a non-inverting input node coupled to a common node, an inverting input node and an output node;
• a first switch coupled between the inverting input and the common node;
• a plurality of switching circuits, each comprising:
• a capacitor coupled between the inverting input node and a first node;
• a second switch coupled between the first node and the input node;
• a third switch coupled to the first node;
• and
• a fourth switch coupled between the first node and the output node, wherein the third switch and the fourth switch are synchronous, and the third switch is turned off and the second switch is turned on when the first switch is turned on, and the first switch and the second switch are turned off when the third switch is turned on;
• and
• a voltage generating unit coupled to the third switch of each of the switching circuits, selectively providing a common signal and a reference signal to the third switches of the switching circuits, wherein the reference signal is independent from the analog signal and the common signal.

An analog to digital converter for converting an input signal to an output signal, comprising:

• a track and hold amplifier receiving the input signal to generate a sampled signal, and comprising:
• an input node receiving the analog signal;
• an amplifier having a non-inverting input node coupled to a common node, an inverting input node and an output node;
• a first switch coupled between the inverting input and the common node;
• a plurality of switching circuits, each comprising:
• a capacitor coupled between the inverting input node and a first node;
• a second switch coupled between the first node and the input node;
• a third switch coupled to the first node;
• and
• a fourth switch coupled between the first node and the output node, wherein the third switch and the fourth switch are synchronous, and the third switch is turned off and the second switch is turned on when the first switch is turned on, and the first switch and the second switch are turned off when the third switch is turned on;
• and
• a voltage generating unit coupled to the third switch of each of the switching circuits, selectively providing a common signal and a reference signal to the third switches of the switching circuits, wherein the reference signal is independent from the analog signal and the common signal;
• and
• a quantizer quantizing the sampled signal to generate a quantized signal;
• and
• a calibration processor calibrating the quantized signal to generate the output signal.