Temperature sensing circuit and method using dll

Abstract

A temperature sensing circuit using a delay locked loop and a temperature sensing method. The temperature sensing circuit includes a locked delay unit for receiving an external clock and generating a locked delay pulse keeping a constant delay amount regardless of temperature. A variable delay unit may have a chain structure of a plurality of delay cells depending upon temperature. The variable delay unit may receive the external clock and generate variable delay pulses having respectively different delay amounts based on temperature. A decision control unit is configured to sense a determination temperature by using a phase difference between one selected from the variable delay pulses and the locked delay pulse. Accordingly, an unnecessary time and cost causable by temperature compensation can be reduced, and an automatic temperature compensation and a precise temperature sensing operation can be obtained.