Method for Speeding a Differential Operational Amplifier in the Invert Connection Circuit

Abstract

A method for increasing the slew-rate (SRHS) in the invert connection of an operational amplifier (OA) with a dual-input-stage is proposed. The principle of the method includes introduction of two nonlinear differentiating correction circuits (DCc) of the transient into the classical OA circuit which form additional overcharge currents of the integrating capacitance of the OA correction in the high-signal operation. At the same time, the DCcs practically don't affect the small-signal response of the OA. The OA circuits of the proposed subclass can have a low consumption current in the steady-state behavior and be performed on the basis of typical technological processes (CMOS, BiJFet, BJT, SiGe, etc.). The results of computer modeling of BJT OA on integrated transistors of JSC “SPE Pulsar” (Moscow) show that the SRHS of the inverting OA, with ideal current mirrors and the buffer amplifier, increases more than 15 times (to 20,000 V/µs).