Self-bootstrapping transducer interface
AssigneeADE Corporation
InventorRoy E. Mallory
Life of this patent
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Abstract
A mechanism to provider a bootstrapped power source for a differential operational amplifier includes a three-winding transformer having a first winding disposed between a positive voltage and a plus power input to the amplifier, yielding an initial plus voltage, a second winding disposed between a negative voltage and a minus power input to the amplifier yielding an initial minus voltage, and a third winding disposed between a ground and a plus input to the amplifier providing a feedback path. The differential operational amplifier output is connected to ground. The said amplifier minus input is connect to a signal and when the signal is displaced a first amount from a first voltage, the plus and minus power inputs are displaced approximately the same amount from the initial positive and negative voltages.
Claims7
A mechanism to provide a bootstrapped power source for a differential operational amplifier having a plus and a minus input, a plus and a minus power input and an output, said mechanism comprising:
- a three-winding transformer, a first winding of said three windings disposed between a positive voltage and said plus power input yielding an initial plus voltage, a second winding of said three windings disposed between a negative voltage and said minus power input yielding an initial minus voltage, and a third winding of said three windings disposed between a ground and said plus input providing a feedback path;
- said differential operational amplifier output connected to said ground;
- and
- said differential operational amplifier minus input connected to a signal, wherein when said signal is displaced a first amount from a first voltage, said plus and minus power inputs are displaced said first amount from said initial positive voltage and said initial minus voltage.
A method of providing a bootstrapped power source for a differential operational amplifier using a three-winding transformer comprising:
- connecting an output of said differential operation differential operational amplifier to ground;
- connecting a first winding of said transformer between a positive power source and a positive power input of said differential operational amplifier;
- connecting a second winding of said transformer between a negative power source and a negative power input of said differential operational amplifier;
- and
- connecting a third winding of said transformer between a ground and a positive input of said differential operational amplifier.
A capacitive displacement sensor comprising:
- an excitation source;
- an amplifier configured as a buffer;
- a reference capacitor coupled between one end of said excitation source and a negative input of said buffer;
- a probe capacitor connected between said negative input of said amplifier and ground;
- an output of said amplifier connected to ground;
- a first winding of a three-winding transformer connected between a positive voltage and a positive power connection of said amplifier;
- a second winding of said three-winding transformer connected between a negative voltage and a negative power connection of said amplifier;
- and
- a third winding of said three-winding transformer connected between ground and a positive input of said buffer, said positive input of said buffer further connected to a guard of said probe capacitor.
A unitary-gain amplifier providing an output that mirrors an input comprising:
- a differential amplifier biased for unitary gain;
- an output of said differential amplifier connected to ground;
- said input connected to a negative input of said differential operational amplifier;
- a first winding of a three-winding transformer connected between a positive power source and a positive power input of said differential operational amplifier;
- a second winding of said three-winding transformer connected between a negative power source and a negative power input of said differential operational amplifier;
- and
- a third winding of said three-winding transformer connected between a ground and a positive input of said differential operational amplifier, wherein said positive input is an output of said amplifier.
A mechanism to provide a bootstrapped power source for a differential operational amplifier having a plus and a minus input, a plus and a minus power input and an output, said mechanism comprising:
- a three-winding transformer, a first winding of said three windings disposed between a positive voltage and said plus power input yielding an initial plus voltage, a second winding of said three windings disposed between a negative voltage and said minus power input yielding an initial minus voltage, and a third winding of said three windings disposed between a stable reference and said plus input providing a feedback path;
- said differential operational amplifier output connected to said stable reference;
- and
- said differential operational amplifier minus input connected to a signal, wherein when said signal is displaced a first amount from a first voltage, said plus and minus power inputs are displaced said first amount from said initial positive voltage and said initial minus voltage.
Dependencies are inferred from the claim text.