Comment on “A nonlinear CMOS analog cell for VLSI signal and information processing”

For original paper see Khachab et. al., ibid., vol.26, p.1689 (1991) In the title paper, a reference to Tsividis et. al. (1986) has been given following the mention of the four-MOSFET, crosscoupled, triode-operated transconductor with two control voltages. To avoid the possibility of misunderstanding on the part of readers, we would like to state that we were not involved in the invention of this circuit (which is to be distinguished from its two-transistor precursor). This circuit was made known to us in April 1985 by Z.Czamul. He proposed the above four transistor circuit, detailed its several advantages, and laid the foundations for its use in several ways