A high-temperature comparator with rail-to-rail input voltage range

A high-temperature comparator with rail-to-rail input voltage range is presented. The design uses a 0.5-μm silicon-on-insulator (SOI) technology. The rail-to-rail operation is achieved using two folded-cascode differential amplifiers operating in parallel as an input stage. The output of the appropriate amplifier is connected to the comparator output through a logic-controlled analog multiplexer. The simulations show that the comparator remains operational over the full rail-to-rail common-mode input voltage range, with somewhat degraded input offset voltage for input voltages close to either supply voltage.