Time-domain temperature sensor based on interlaced hysteresis delay cells

This paper presents a low power and small area temperature sensor with interlaced hysteresis delay cells (IHDCs) instead of using inverter-based buffers. IHDC consumes lower power and occupies smaller silicon area than inverter-based buffers. A pulse width which is proportionate to temperature is produced by the proposed temperature-to-pulse generator. Two different delay lines and an XOR gate are employed to detect pulse width for temperature measurement. Temperature dependent and thermal insensitive delay lines are used as the two different delay lines. The output of the temperature-to-pulse generator is converted to digital output by a time-to-digital converter. This temperature sensor is simulated with 0.18um CMOS technology and 1.8V supply voltage, and it shows a good linearity with lower power consumption compared to conventional ones. The proposed temperature sensor consumes 1.185 mW.