A new rail-to-rail ultra low voltage high speed comparator

This paper presents a new rail-to-rail input highperformance regenerative comparator suitable for low-voltage low-power applications, e.g. bio-implantable circuits. In this circuit the body of the PMOS transistor is used as comparator's input. A technique is proposed to increase the speed of the circuit. The proposed comparator has a good performance in weak inversion (sub-threshold). Simulations are done in the 0.18-μm CMOS technology with a supply voltage of 0.5 V. The propagation delay time of the second proposed comparator is 16.4 ns, the power dissipation is 20 nW and the power delay product is 0.33 fJ in clock frequency of 5 MHz and input voltage of 500 μV. Also the supply voltage can be decreased to 0.3 V.