Analog Devices,inc.

Daniel F Kelly

Lawrence A Singer

Franklin Marshall Murden, Ii

Steven J Decker

Stephen Robert Kosic

Daniel Rey-Losada

A common mode feedback (CMFB) loop for a differential amplifier sense an output common mode of a differential circuit and provides feedback to the gates of tail current transistors. Many CMFB loops cannot easily adjust the output common mode voltage and the output common mode may vary over process, voltage, and temperature. An improved CMFB circuit adds a control circuit to control backgates of tail current transistor device(s) of the differential circuit such that the output common mode voltage can be made adjustable.

Common mode feedback circuit with backgate control

An example embodiment of an active cascode circuit has a control circuit for control of the gate to source voltage (VGS) of at least one transistor in the active cascode circuit. The embodiment may be configured so that control of the VGS also controls the voltage Vin on the input. Vin may be adjusted without altering the device geometry or changing the drain current. This allows for better control and optimization of available headroom for the input voltage in low voltage designs and also results in higher active cascode circuit bandwidth and/or higher output impedance (Rout) for a given power level.

Active cascode circuit using backgate control

A programmable clock booster system including a clock booster circuit including at least one boost capacitor connected between a first node and a second node for sampling an input voltage in a first phase and applying a boosting voltage to said second node during a second phase, and a programmable capacitor circuit connected to said first node for providing a programmable boosted voltage on said first node during said second phase.

Programmable clock booster system

A differential two-stage Miller compensated amplifier system with capacitive level shifting includes a first stage differential transconductance amplifier including first and second output nodes and an output common mode voltage, a second stage differential transconductance amplifier including non-inverting and inverting inputs and outputs and an input common mode voltage, and a level shifting capacitor circuit coupled between the first and second output nodes and the non-inverting and inverting inputs for level shifting between the output common mode voltage of the first stage and the input common mode voltage of the second stage.

Differential two-stage miller compensated amplifier system with capacitive level shifting

An input tracking current mirror for a differential amplifier system includes a current mirror having an input leg and an output leg, a differential amplifier including a first set of at least two transconductance components, each having at least one input terminal for receiving input signals, the first set of at least two transconductance components having a first common node connected to the output leg which has a first voltage that is a function of the input signals, and a tracking circuit including a second set of at least two transconductance components each having at least one input terminal for receiving the input signals, the second set of at least two transconductance components, having a second common node connected to the input leg which has a second voltage that is a function of the input signals, the tracking circuit driving the second voltage on the input leg to track the first voltage on the output leg with variations in the input signals.

Growing community of inventors

Andover, MA, United States of America

Daniel F Kelly