An active-feedback cascode current source

An MOS cascode current source that employs both active and passive series feedback is reported. Small-signal analysis and SPICE simulation results show that a CMOS implementation of the active-feedback cascode current source provides an output open-circuit Thevinin voltage greater than 10/sup 6/ V. This represents an increase of about two orders of magnitude as compared with the conventional cascode current source. The active-feedback cascode current source maintains the same output voltage swing range as the conventional double cascode. >