a low voltage bjt-based temperature sensor with duty cycle modulated output with fom resolution of about 1.4pj. ◦c2 and inaccuracy of ±0.11 ◦c (3σ) from −55 ◦c to 130 ◦c

This paper presents a low voltage bjt-based smart temperature sensor with duty cycle modulated output and inaccuracy of ±0.11 ◦c (3σ) and fom resolution of about 1.4pj. ◦c2 from −55◦c to 130◦c. this sensor can work with a supply voltage of 1.5v. it uses a bjt-based front-end to generate a proportional to absolute temperature voltage (vptat) and a complementary to absolute temperature voltage (vctat), which are then modulated to a duty-cycle output. adding an integrator before the schmitt trigger has increased the range of input changes of the schmitt trigger. as a result, the hysteresis of the schmitt trigger can be increased and it has better noise immunity. implemented in a standard 0.18-µm cmos process, the sensor has an active area of about 0.64mm2 and can work with 1.5v from -55◦c to 130◦c with an inaccuracy of ±0.11◦c (3σ). power consumption is about 45uw.