This paper presents a novel integrated temperature sensor structure that utilizes a built-in feedback loop. The structure does not require any additional references, and it embeds the successive approximation logic from the SAR ADC into the temperature sensor circuit, eliminating the need for an external analog-to-digital converter. Consequently, the proposed structure is simpler and faster in converting temperature to digital code values than conventional integrated temperature sensors. The sensor is implemented in 90 nm CMOS technology. An inaccuracy of ±0.58 °C is achieved across a temperature range of -20 °C to 100 °C. With a conversion time of 0.7 μs, the temperature sensor can convert to a digital code value in a very short period of time. Additionally, with a conversion time of 0.7 ms, a resolution of 0.18 °C is achieved.