Bipolar complementary sequence pairs of Types II and III are defined, enumerated for n ≤ 28, and classified. Type-II pairs are shown to exist only at lengths 2m, and necessary conditions for Type-III pairs lead to a non-existence conjecture regarding their length.

A parallel current-mode multilevel identifying circuit for flash memories is proposed. The sensing scheme based on the CMOS cross-coupled structure modified from the clamped bit-line sense amplifier achieves high speed and low power dissipation. The offset of the proposed sense amplifier due to mismatch is also reduced significantly. The circuit has been fabricated using 0.6 µm CMOS technology. The simulation and measurement indicate the sensing speed reaches 1 ns at 3 V supply voltage with average power consumption about 2 mW at 50 MHz.

Based on cyclic difference sets, sequences with two-valued autocorrelation can be constructed. Using these constructed sequences, two classes of binary constant weight codes are presented. Some codes proposed in this paper are proven to be optimal.