A Novel High Performance CMOS Current Switch Drive

The influence of current switch driver output resistance and glitch energy mechanism for D/A converter are analyzed, and the principle of current switch driver design is proposed. Based on the proposed design principle, a novel simple high performance current switch driver is proposed. It comprises four NMOS transistor, two PMOS transistor and a substrate bias capacitor. The introduction of bias capacitor not only lowers swing switch signal for restraining the capacitive coupling of the control signals, but also restrains the influence of substrate noise for analog blocks. By changed the size of PMOS transistors, the cross points of control signals and output signals are lowered for the dynamic performance of D/A converter. Simulation results based on TSMC 0.35 mu m CMOS technology BSIM3V3 model show that the driver have about 250ps setting time and good dynamic performance, it is very suitable for high speed, high resolution current steering D/A converter.