A First-Order All-Pass Filter Based on the Current Differential Amplifier

In this work the design and implementation of a first-order all-pass filter (APF) based on the current differential amplifier is presented. The proposed APF is composed by only seven MOS transistors and one capacitor. One major advantage is that the current-mode signal is only processed by NMOS transistors while avoids any extra PMOS signal paths. Due to its compactness, this APF can operate under nominal and low voltage supply, allowing high-frequency or low-voltage low-power operation modes. To validate the propose circuit a high-frequency and a low-voltage low-power APFs were designed and simulated using a 0.18 μm TSMC CMOS technology under Cadence Virtuoso environment.