A high-speed comparator design technique

Fast comparators are an essential feature of many new circuit applications, including optical fiber links, nucleonics, and data converters. The author describes a design approach based on large signal linear circuitry which is capable of providing high gain (>55 dB), low propagation delay (1.5 ns) comparators, either singly or for use in arrays. Outstanding features of the circuit are high gain at high frequency and the minimal variation of delay with overdrive conditions. A junction isolated bipolar process is used which has 3 /spl mu/m minimum feature size and 5 GHz transistor f/SUB T/´s.