This　paper　presents　a　high-speed　and　high-precision　time-domain　comparator　integrated　circuit.　The　proposed　comparator　adopts　a　voltage-controlled　oscillator　circuit　and　a　time　amplifier,　to　convert　the　analog　input　voltage　to　a　phase　difference　in　time　domain　with　high　precision.　By　introducing　a　feedback　for　VCO　and　using　the　phase　detector　in　the　following　stage　to　judge　the　phase　differences　between　two　signals　directly,　the　input　signals　can　be　compared　in　a　high　speed.　The　comparator　is　designed　in　SMIC　0.18　mu　m　CMOS　process　technology.　The　simulation　results　show　that　under　1　V　power　supply,　this　comparator　achieves　0.1　mu　V　accuracy,　181　MHz　maximum　response　speed,　and　86　mu　W　power　consumption.