Improved PSRR and Output Voltage Swing Characteristics of Folded Cascode OTA

Mixed and analog systems design with high performance suffers from many difficulties due to supply voltage, power consumption and area overhead. A need for low-voltage low-power operational amplifiers exists and used for some applications. This paper deals an effective OTA design for good PSRR, low-voltage, low-power and wide output voltage swing operational amplifier. Trying to combine an alternative technique of voltage driven-Bulk CMOS with a folded cascade OTA design to improve PSRR and output voltage swing in that circuit by reducing its supply voltage and power consumption. Two principles input voltage for OTA are used and applied at the bulk of the differential pair, showing its advantages and disadvantages, discussing further problems that have to be solved for better performance. The presented Folded Cascode OTA designs; bulk driven and gate driven structure, are implemented using a 0.35μm CMOS technology and the supply voltage 2V. These two architectures have been compared, using cadence spectrum simulations, in this paper along with drawbacks and advantages of each. The obtained results showed the good performances of the Folded Cascode Bulk Driven OTA; this is compared with classic OTA design.