An operational amplifier including an input stage coupled to an input terminal, an output stage coupled to an output terminal, and a gain node between the input stage and the output stage. A bias current source is couplable to the input stage to supply a bias current thereto and a current mirror circuit mirrors the bias current toward the gain node and the output stage. A switch circuit includes a switch activatable to bring the gain node to a pre-bias voltage and a switch coupled to the output stage and switchable between a first state and a second state in which the output stage is active and non-active, respectively. A further switch circuit is coupled to the output terminal and switchable between a first state and a second state in which the output stage is coupled to the output terminal and to a reference level, respectively.

An operational amplifier including an input stage coupled to an input terminal, an output stage coupled to an output terminal, and a gain node between the input stage and the output stage. A bias current source is couplable to the input stage to supply a bias current thereto and a current mirror circuit mirrors the bias current toward the gain node and the output stage. A switch circuit includes a switch activatable to bring the gain node to a pre-bias voltage and a switch coupled to the output stage and switchable between a first state and a second state in which the output stage is active and non-active, respectively. A further switch circuit is coupled to the output terminal and switchable between a first state and a second state in which the output stage is coupled to the output terminal and to a reference level, respectively.

A gate pulsing gate ladder circuit includes a series connected resistor ladder with bond pads connected to the resistor ladder between adjacent resistors. An electrical node is positioned between a first and second resistor of the resistor ladder. The electrical node is electrically connected to a gate electrode of a field effect transistor (FET). A power supply produces a constant power voltage that is applied to a pre-selected bond pad to produce a desired bias voltage at the gate electrode of the FET. A selectable gate enable voltage source is connected to an and of the resistor ladder at the first resistor and is configured to produce a first and second voltage level that when combined with the constant power voltage produces a voltage level that causes the FET to be in a conducting state or non-conducting state, respectively.