Pre-driver stage with adjustable biasing
AssigneeTexas Instruments Incorporated
InventorMartijn Fridus Snoeij
Life of this patent
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Abstract
An electrical system includes a power supply and an electrical circuit coupled to the power supply and including an operational amplifier. The operational amplifier includes an input stage and a pre-driver stage coupled to the input stage, wherein the pre-driver stage includes a first input terminal, a second input terminal, and a voltage supply terminal. The operational amplifier also includes an output stage with bipolar transistors coupled to the pre-driver stage. The pre-driver stage is configured to: detect a voltage differential across the first and second input terminals of the pre-driver stage; and provide an adjustable bias current based on the voltage differential.
Claims22
An electrical system, comprising:
- a power supply;
- an electrical circuit coupled to the power supply and including an operational amplifier with:
- an input stage;
- a pre-driver stage coupled to the input stage, wherein the pre-driver stage includes a first input terminal, a second input terminal, and a voltage supply terminal;
- and
- an output stage with bipolar transistors coupled to the pre-driver stage, wherein the pre-driver stage is configured to:
- detect a voltage differential across the first and second input terminals of the pre-driver stage;
- and
- provide an adjustable bias current based on the voltage differential.
An operational amplifier, comprising:
- an input stage;
- and
- a pre-driver stage coupled to the input stage, wherein the pre-driver stage includes:
- a first input terminal;
- a second input terminal;
- and
- a bias current control circuit coupled to the first and second input terminals and configured to provide an adjustable bias current based on a voltage differential across the first and second input terminals;
- and
- an output stage with bipolar transistors coupled to the pre-driver stage.
A pre-driver circuit, comprising:
- first and second input terminals;
- a class-AB bias current generator configured to output a control current as a function of a voltage differential across the input terminals;
- and
- a current mirror coupled to the class-AB bias current generator, wherein the current mirror is configured to add an adjustable bias current to a fixed bias current of the pre-driver circuit based on the control current.
Dependencies are inferred from the claim text.