A power efficient and digitally assisted CMOS complementary telescopic amplifier with wide input common mode range

Telescopic amplifiers are often preferred for their large DC gain, low power dissipation and low flicker noise. On the other side, they suffer from serious problems like poor input common mode range and output swing. In this work, a simple technique to extract improved common mode range from telescopic structure is presented. To achieve this, two telescopic amplifiers using complementary differential pairs are utilized. The proposed design incorporates a digital switching technique which allows switching between high performance and low power modes. Low power mode allows reduction in power dissipation with compromise on elevated performance parameter. The entire design is verified using UMC 180 nm CMOS technology and the simulation results are presented.