Comments on 'CMOS differential difference current conveyors andtheir applications'

摘要

For original paper see ibid., vol. 143, no. 2, p. 91-96 (1996 ).nRecently Chiu, Liu, Ivan and Chen introduced a new active building blockncalled a differential difference current conveyor (DDCC) andndemonstrated its application in realising squarer, square rooter andnmultiplier circuits, differential integrators, and voltage mode (VM) andncurrent mode (CM) low-pass/band-pass (LP/BP) filters. CMOS integrablenimplementations for DDCC+ and DDCC- (two separatencircuits) were also proposed. This comment extends the domain ofnapplication of the DDCC to the realisation of CM all grounded passivenelements (AGPE) SRCOs, not discussed by Chiu et al. or anyone else sonfar. In particular, we show that, if instead of considering DDCC+n and DDCC- as separate units, we consider a single unitnwhich we call a differential difference complementary current conveyorn(DDCCC), then such a DDCCC turns out to be a versatile device tonimplement CM AGPE SRCOs