Dual-Input Folded Cascode Amplifier for Higher Slew Rate

The amplifier is divided into two separate input circuits: a first input circuit with PMOS transistors for positive input signals and a second input circuit with NMOS transistors for negative input signals. Each input circuit has dedicated current mirrors and regulation transistors that operate independently, allowing simultaneous charging and discharging of the load capacitance without interfering with each other, thereby achieving high slew rate and maintaining linearity.

The amplifier is segmented into two independent input circuits with opposite polarities, where the first input circuit handles positive signals and the second handles negative signals. This segmentation enables rail-to-rail input operation by allowing both circuits to operate simultaneously across the full supply voltage range, significantly expanding the input range while maintaining manageable circuit complexity through modular design.

The single input pair is segmented into two separate input pairs: a first input pair with PMOS transistors and a second input pair with NMOS transistors. Each input pair is equipped with its own current mirror and regulation transistor, allowing independent current control. This segmentation enables the slew rate to be enhanced beyond the conventional limit by providing separate charge and discharge current paths, while the modular structure keeps the overall circuit complexity manageable.

The first input circuit with PMOS transistors and the second input circuit with NMOS transistors are merged into a unified folded cascode amplifier structure. Both circuits share common elements such as the load capacitance, output node, and power supply connections, while maintaining independent signal paths. This merging approach allows the dual input circuits to work together synergistically, achieving enhanced slew rate through simultaneous charging and discharging operations while avoiding the full complexity of completely separate circuits.