Slew-rate boost circuitry
AssigneeSemiconductor Components Industries, LLC
InventorsCatalin Ionut Petroianu, Alexandra-Oana Petroianu
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Abstract
The techniques described herein relate to a circuit including an operational amplifier that includes a differential amplifier, a capacitor, and an output stage. The differential amplifier includes a first input and a second input. The output stage is configured to generate an output voltage. The circuit includes a slew-rate boost circuitry connected to the operational amplifier. The slew-rate boost circuitry is configured to detect a voltage differential between the first input and the second input and apply, at an output of the differential amplifier, a boost current to charge the capacitor during a period of time in which the output voltage increases or decreases to a target voltage level.
Claims20
A circuit comprising:
- an operational amplifier including a differential amplifier, a capacitor, and an output stage, the output stage configured to generate an output voltage;
- and
- a slew-rate boost circuitry connected to the operational amplifier and including a first boost transistor connected to a first output of the differential amplifier and a second boost transistor connected to a second output of the differential amplifier, the slew-rate boost circuitry is configured to:
- detect a voltage differential between a first input of the differential amplifier and a second input of the differential amplifier;
- and
- apply, at an output of the differential amplifier, a boost current to charge the capacitor during a period of time in which the output voltage changes from a first voltage level to a second voltage level, the boost current being generated by the first boost transistor and the second boost transistor.
A circuit comprising:
- an operational amplifier including a differential amplifier, a capacitor, and an output stage, the output stage configured to generate an output voltage;
- a first control circuitry including a first boost transistor connected to a first output of the differential amplifier and a second boost transistor connected to a second output of the differential amplifier, the first control circuitry configured to:
- apply, at an output of the differential amplifier, a first boost current to charge the capacitor during a first period of time in which the output voltage changes from a first voltage level to a second voltage level, the first boost current being generated by the first boost transistor and the second boost transistor;
- and
- a second control circuitry configured to apply, at the output of the differential amplifier, a second boost current to charge the capacitor during a second period of time in which the output voltage changes from the second voltage level to the first voltage level.
A method for increasing a slew-rate of an operational amplifier, the method comprising:
- detecting a first voltage differential between a first input of a differential amplifier and a second input of the differential amplifier;
- generating a first boost current using a first boost transistor and a second boost transistor, the first boost transistor being connected to a first output of the differential amplifier, the second boost transistor being connected to a second output of the differential amplifier;
- applying, at an output of the differential amplifier, the first boost current to charge a capacitor during a first period of time in which an output voltage changes from a first voltage level to a second voltage level;
- detecting a second voltage differential between the first input and the second input;
- and
- applying, at the output of the differential amplifier, a second boost current to charge the capacitor during a second period of time in which the output voltage changes from the second voltage level to the first voltage level.
Dependencies are inferred from the claim text.