Operational transconductance amplifier (ota) with separate cascode paths for reconfigurable input pairs

An operational transconductance amplifier (OTA), comprising:

• a first input p-channel field effect transistor (PFET) including a gate configured to receive a first signal;
• a second input n-channel field effect transistor (NFET) including a gate configured to receive the first signal;
• a first set of one or more input PFETs including a first set of one or more gates coupled to the gate of the first input PFET in a first mode of operation, wherein the first set of one or more gates of the first set of one or more input PFETs are decoupled from the gate of the first input PFET in a second mode of operation;
• a first set of one or more input NFETs including a first set of one or more gates coupled to the gate of the first input NFET in the first mode of operation, wherein the first set of one or more gates of the first set of one or more input NFETs are decoupled from the gate of the first input NFET in the second mode of operation;
• a first cascode PFET including a source coupled between the first set of one or more input PFETs and the first set of one or more input NFETs, wherein the first cascode PFET is enabled in the first mode of operation, and disabled in the second mode of operation;
• and
• a second cascode PFET including a source coupled to the first input PFET in the first mode of operation and to both the first input PFET and the first input NFET in the second mode of operation, wherein the second cascode PFET is disabled in the first mode of operation, and enabled in the second mode of operation.

A method of generating a first output signal and a second output signal, comprising:

• applying a first input signal to a first set of input field effect transistors (FETs) in a first mode of operation of an operational transconductance amplifier (OTA);
• coupling a first cascode FET to the first set of input FETs to generate the first output signal at a drain of the first cascode FET in the first mode of operation;
• applying a second input signal to a subset of one or more of the first set of input FETs in a second mode of operation of the OTA;
• and
• coupling a second cascode FET to the subset of one or more of the first set of input FETs to generate the second output signal at a drain of the second cascode FET in the second mode of operation.