Indirect compensation technique based two-stage recycling folded cascode amplifier for reconfigurable multi-mode sigma-delta ADC

Typical and proposed recycling folded cascade (RFC) amplifier have been designed in TSMC 0.18 μm. Simulated and measured results are compared. Proposed RFC demonstrate an enhancement on DC gain by 5 dB almost for the same power consumption and bandwidth. Moreover, it realized less input referred noise than typical. Split-length devices (SLD) method is applied on proposed (RFC) to create a low impedance node employed in indirect feedback compensation. Realization of two-stages recycling folded cascade amplifier using indirect feedback compensation method has been designed. The proposed two-stages amplifier delivers open loop gain 83 dB enhanced by 20 dB over typical one, gain bandwidth product is 187 MHz and slew rate is 74 V/μs which is required for reconfigurable multi-mode sigma-delta ADC to attain high SNR and SNDR.