Analog design procedures for channel lengths down to 20 nm

A new design procedure is derived for analog design with MOSTs in all three regions of operation i.e. strong and weak inversion and velocity saturation. BSIM6/EKV model parameters are used. Optimum biasing points are derived for single- and two-stage amplifiers. It is shown that for channel lengths around 20 nm, a unique optimum is achieved for the fT × gm/IDS Figure of merit. At such low channel lengths noise and distortion establish severe limitations in dynamic range. They can be mitigated by the use of negative resistors, as used in an increasing number of amplifier and filter configurations. An overview is given of such circuit configurations.