Operational amplifier having improved slew rate

A method for improving a slew rate of an operational amplifier, comprising:

• detecting the onset of a slewing operation with a comparator separate from the operational amplifier;
• activating at least two out of at least four additional current sources during the slewing operation to improve the slew rate in response to an output of the comparator;
• and
• deactivating the at least two out of the at least four additional current sources when no slewing operation is detected in response to a change in the output of the comparator, thereby minimizing additional power dissipation from additional current flow.

A slew rate improvement circuit for an operational amplifier, comprising:

• a current booster circuit comprising a first current source, a second current source, a third current source, and a fourth current source;
• and
• a comparator circuit comprising a first comparator and a second comparator, wherein the first comparator has a non-inverting input, an inverting input and an output, the non-inverting input coupled to a first voltage input and the inverting input coupled to a second voltage input, wherein the second comparator has a non-inverting input, an inverting input and an output, the non-inverting input coupled to the second voltage input and the inverting input coupled to the first voltage input;
• wherein the outputs of the first and second comparators control the first, second, third and fourth current sources to supply additional current improving the slew rate of the operational amplifier circuit.