A Novel Slew-Boosting Circuit for Rail-to-Rail Operational Amplifier

摘要

In order to improve the slew rate of rail-to-rail operational amplifiers, this paper presents a novel slew boosting circuit. Two slew-boosting unit circuits are proposed to provide large compensation current by directly detecting the differential level change at the input terminals of the amplifier. Accordingly, the slewing performance is dynamically boosted. In each slew-boosting unit circuit, tunnel diodes are used to replace the conventional MOS transistors as loads. This circuit is designed in 1.0 mu m TVS process. Measurement results show that the rail-to-rail operational amplifier achieves a positive slew rate of 164 V/ps and negative slew rate of 185 V/mu s.