This paper introduces an MOS-based intelligent temperature sensor with a linear readout. Compared with similar designs, the proposed sensor utilizes the DIBL effect to reduce the precision requirement for the voltage reference source and compensate for the temperature measurement range. A compact voltage reference circuit is introduced, which generates two reference voltage bases using only three transistors. In addition, the proposed digital readout circuit does not require a subtractor or a divider, further saving area. Fabricated in a 55 nm CMOS process, the proposed sensor occupies a compact area of 3216 μm2. Post-simulation results show it has a maximum error of −0.52/+0.28 °C within the temperature range of −20 °C to 120 °C after two-point calibration. The power supply voltage range of the sensor is 0.8 to 1.8 V. It has a maximum voltage sensitivity of 5.7 °C/V and its power consumption is only 166 nW, with a power supply voltage of 0.8 V.