1-V CMOS comparator for programmable analog rank-order extractor

A CMOS rail-to-rail comparator operating at low-voltage supply and obtained by using a conventional fabrication process is proposed. Based on the comparator, an analog rank-order extractor with k winner-take-all capability is presented. An experimental chip was fabricated using 0.5 (mu)m CMOS technology. Measured results at 1-V supply voltage show a comparator response time of 4 (mu)s for 10-mV precision and that, within 4 (mu)s, the extractor successfully identifies a 100-mV differential voltage among inputs to find a rank order of the input set.