US 10,333,478 B1Granted

Slew boost disable for an operational amplifier

AssigneeTexas Instruments Incorporated

InventorsMartijn Fridus Snoeij, Sudarshan Udayashankar

Life of this patent

Estimating the term…

Loading patent…

Abstract

An input stage of an operational amplifier receives first and second input voltages. An output slew detection circuit decreases a first current responsive to slewing of an output of the operational amplifier and increases the first current responsive to no slewing. A slew boost and differential input voltage detection generates a second current at a first level when the first and second input voltages are approximately equal and to generate the second current at a second level, smaller than the first level, responsive to the first and second input voltages not being approximately equal. A voltage on a capacitor increases responsive to the first current from the output slew detection circuit increasing and responsive to the second current being at the second level. A current mirror is activated responsive to the voltage on the capacitor exceeding a second threshold. The current mirror decreases a third current of the input stage.

Claims18

Dependent claims

An operational amplifier, comprising:

an input stage configured to receive a first input voltage and a second input voltage;
an output slew detection circuit configured to increase a first current responsive to slewing of an output voltage of the operational amplifier and to decrease the first current responsive to the output voltage not slewing;
a slew boost and differential input voltage detection circuit coupled to the input stage and configured to increase a second current responsive to a difference between the first and second input voltages;
a first capacitor coupled to the output slew detection circuit and the slew boost and differential input voltage detection circuit;
and
a first current mirror coupled to the first capacitor, wherein a voltage on the first capacitor is configured to increase responsive to the first current from the output slew detection circuit increasing and separately responsive to the second current;
and
wherein the first current mirror is configured to be turned on responsive to the voltage on the first capacitor exceeding a threshold, and wherein once turned on, the first current mirror is configured to cause a third current of the input stage to decrease.

5 more elements

Dependencies are inferred from the claim text.