Operational transconductance amplifier, reconfigurable fully differential voltage sensing amplifier and reconfigurable fully differential capacitive sensing amplifier

A fully differential voltage sensing amplifier, comprising:

• an operational transconductance amplifier, the operational transconductance amplifier comprising:
• a cascode differential-pair amplifying circuit, configured for receiving a differential input voltage, and for providing a differential output voltage;
• a bias driving circuit, electrically connected with the cascode differential-pair amplifying circuit, the bias driving circuit being configured for providing a first bias current to drive the cascode differential-pair amplifying circuit, and for adjusting the transconductance of the operational transconductance amplifier, wherein the bias driving circuit comprises a first floating-gate transistor, the first floating-gate transistor being configured for adjusting the first bias current;
• and
• a common mode feedback circuit, electrically connected with the cascode differential-pair amplifying circuit, the common mode feedback circuit being configured for adjusting a second bias current of the cascode differential-pair amplifying circuit according to the differential output voltage so that the differential output voltage is stabilized;
• a first feedback resistor;
• a first feedback capacitor, wherein the first feedback capacitor is electrically connected with the first feedback resistor in parallel, and the first feedback capacitor being coupled between a first input node and a first output node of the operational transconductance amplifier;
• a second feedback resistor;
• a second feedback capacitor, wherein the second feedback capacitor is electrically connected with the second feedback resistor in parallel, and the second feedback capacitor being coupled between a second input node and a second output node of the operational transconductance amplifier;
• a first input capacitor, wherein the first input capacitor is coupled between a first input node of the fully differential voltage sensing amplifier and the first input node of the operational transconductance amplifier;
• and
• a second input capacitor, wherein the second input capacitor is coupled between a second input node of the fully differential voltage sensing amplifier and the second input node of the operational transconductance amplifier.

A fully differential capacitive sensing amplifier comprising:

• an operational transconductance amplifier, the operational transconductance amplifier comprising:
• a cascode differential-pair amplifying circuit, being coupled with a differential input capacitor, the cascode differential-pair amplifying circuit being configured for providing a differential output voltage according to the variation of electrical charges generated by the differential input capacitor;
• a bias driving circuit, electrically connected with the cascode differential-pair amplifying circuit, the bias driving circuit being configured for providing a first bias current to drive the cascode differential-pair amplifying circuit, and for adjusting the transconductance value of the operational transconductance amplifier, wherein the bias driving circuit comprises a first floating-gate transistor, the first floating-gate transistor being configured for adjusting the first bias current;
• and
• a common mode feedback circuit, electrically connected with the cascode differential-pair amplifying circuit, the common mode feedback circuit being configured for adjusting a second bias current of the cascode differential-pair amplifying circuit according to the differential output voltage so that the differential output voltage is stabilized;
• a first feedback resistor;
• a first feedback capacitor, wherein the first feedback capacitor is electrically connected with the first feedback resistor in parallel, and the first feedback capacitor being coupled between a first input node and a first output node of the operational transconductance amplifier;
• a second feedback resistor;
• and
• a second feedback capacitor, wherein the second feedback capacitor is electrically connected with the second feedback resistor in parallel, and the second feedback capacitor being coupled between a second input node and a second output node of the operational transconductance amplifier.