High-Speed Operational Amplifier with a Differentiating Circuit of Transient Correction

• Main Authors: Titov, Alexey E., Alferova, Irina A., Kuznetsov, Dmitry V.
• Format: Conference Proceeding
• Language: English
• Subjects: analog-to-digital converter; analog-to-discrete filter; maximum slew rate of output voltage; nonlinear correction; operational amplifier
• ISSN: 2376-6565
• DOI: 10.1109/ElCon61730.2024.10468484

The relevance of the present research is related to the search for promising ideas for increasing the maximum slew rate of the output voltage (\text{SR}_{\text{M}}) of new-generation operational amplifiers (OpAmps). Proposed circuit techniques that provide (with simultaneous use) an increase in \text{SR}_{\text{M}} by more than 2 orders of magnitude. Such high-speed operational amplifiers are in demand today for application in drivers of high-speed ADCs (AD9208, AD9691, etc.), and as active elements in circuits of analog-to-discrete filters on switched capacitors. It is proposed to introduce (according to the developed rules) a nonlinear differentiating RC-circuit realized based on an additional differential stage and a differentiating capacitor of small capacitance into the classical OpAmps with one integrating correction capacitance. Such circuit "additives" practically do not change the low-signal dynamic and static parameters of the OpAmp, and at a large signal during the transient front, when the input stage enters the nonlinear mode, form a large current overcharge of the integrating correction capacitor. Consequently, the \text{SR}_{\text{M}} of the OpAmp is significantly increased.