CIRCUITRY METHODS FOR INCREASING THE SPEED OF OPERATIONAL AMPLIFIERS BASED ON A "FOLDED" CASCODE

Three circuit techniques are proposed that provide (with simultaneous use) an increase bymore than two orders of magnitude the maximum output voltage slew rate (SR) microelectronicoperational amplifiers (op-amps) based on bipolar transistors with a classical architecture,designed to operate in automatic control systems, radio engineering and communications, forexample, as drivers for ultra-high-speed analog-to-digital converters (EVIOAS150, EVIOAS350,AD9208, AD9691, 1273PV14, etc.). The considered op-amps contain cascode input stage anon-linear correction pass-through characteristic tracking increases theattenuation coefficient common-mode signals noise suppression onthe power buses, well intermediate “folded” cascode. use a"folded" makes it possible efficiency using supply voltages, aswell unity gain frequency corrected op-amp. However, such intermediatestage is essential non-linear link limits currents recharge theop-amp capacitor. results computer simulation modifications theAmpSR1, AmpSR2 op amps, which differ from each other structure nonlinear parallelchannel, eliminates dynamic overload "folded" cascode, presented. relevanceof research performed related problems import substitution class ofhigh-speed lack new promising ideas increasing SR op-ampbased differentiating transient circuits thelarge signal mode among analog designers. alsoeffective when CMOS technological processes.