A single-ended BiCMOS sense circuit for digital circuits

The authors present a fast single-ended BiCMOS sense circuit with CMOS output levels which is noise-insensitive enough to be used in a CMOS environment. A bipolar transistor is used in common-emitter configuration. Assuming that the bipolar transistor is conducting current, yet not saturated, a small voltage swing at the base is enough to turn the transistor off, and the collector voltage rises rapidly. An analog current mirror is used to prevent the bipolar transistor from saturating while maintaining a CMOS low-output voltage and to provide noise immunity. The full implementation of the sense circuit is shown.<>