Design of Low-Voltage CMOS Switched-Opamp Switched-Capacitor Systems
Vincent S.L. Cheung, Howard Cam H. Luong1. A generic fast-settling double-sampling SC biquadratic filter architecture is proposed to achieve high-speed operation for SC circuits. 2. A low-voltage double-sampling (DS) finite-gain-compensation (FGC) technique is employed to realize high-resolution SD modulator using only low-DC-gain opamps to maximize the speed and to reduce power dissipation. 3. A family of novel power-efficient SC filters and SD modulators are built based on using only half-delay SC integrators. 4. Single-opamp-based SC systems are designed for ultra-low-power applications. In addition, on the circuit level, a fast-switching methodology is proposed for the design of the switchable opamps to achieve switching frequency up to 50 MHz at 1V, which is improved by about ten times compared to the prior arts. Finally, detailed design considerations, architecture choices, and circuit implementation of five chip prototypes are presented to illustrate potential applications of the proposed multi-phase switched-opamp technique to tackle with and to achieve different stringent design corners such as high-speed, high-integration-level and ultra-low-power consumption at supply voltages of 1V or lower in standard CMOS processes.