Rail-to-rail source followers
AssigneeMarvell International Ltd.
InventorSiew Yong Chui
Life of this patent
Estimating the term…
Abstract
Circuits and methods are provided for producing a rail-to-rail output voltage. A circuit includes a level shifter, a source follower, and a current compensation circuit. The level shifter receives an input signal and applies a compensation voltage to the input signal relative to a voltage level of the input signal in steady-state. The source follower produces an output signal and, responsive to variations in the voltage level of the input signal, changes the voltage level of the output signal using a biasing current. The current compensation circuit, responsive to a difference between the voltage levels of the input and output signals, varies an amount of the biasing current.
Claims36
A circuit, comprising:
- a level shifter to receive an input signal and apply an adjustment voltage to produce a voltage level in an output signal of the circuit during a steady-state that substantially equates a voltage level of the input signal during a steady-state;
- a source follower in communication with the level shifter, the source follower producing an output signal and, responsive to variations in the voltage level of the input signal during a transient state, changing the voltage level of the output signal using a biasing current;
- and
- a current compensation circuit, in communication with the source follower and receiving the input and output signals and, responsive to a difference between the voltage levels of the input and output signals, the current compensation circuit varying an amount of the biasing current.
A method, comprising:
- receiving an input signal;
- applying an adjustment voltage to produce a voltage level in an output signal of the circuit during a steady-state that substantially equates a voltage level of the input signal during a steady-state;
- responsive to variations in the voltage level of the input signal during a transient state, changing the voltage level of the output signal using a biasing current;
- and
- responsive to a difference between the voltage levels, of the input and output signals, varying an amount of biasing current.
A circuit, comprising:
- means for receiving an input signal;
- means for, in communication with the means for receiving, applying an adjustment voltage to produce a voltage level in an output signal of the circuit during a steady-state that substantially equates a voltage level of the input signal during a steady-state;
- responsive to variations in the voltage level of the input signal during a transient state, means for, coupled to the means for applying, changing the voltage level of the output signal using a biasing current;
- and
- responsive to a difference between the voltage levels, of the input and output signals, means for, coupled to the means for changing, varying an amount of biasing current.
Dependencies are inferred from the claim text.