In this paper we propose a temperature sensor, based on a voltage to time converter cell (VTC). A VTC is frequently employed in time to digital converters for generating a delay that is proportional to the input voltage. The delay can then be digitized using a simple ripple counter at the output driven by a temperature independent clock. The power consumption of the proposed sensor is extremely low at 250nW, with an inaccuracy of +0.8 degrees C to -1.5 degrees C after two point calibration. A comparator with switchable bias currents is used to reduce the power consumption, while the temperature compensated current source is implemented using a low power current source. The sensor also exhibits high linearity over the 0 to 100 degrees C temperature range, while being powered by a 1.8V supply.
|Title of host publication||2013 25TH INTERNATIONAL CONFERENCE ON MICROELECTRONICS (ICM)|
|Publication status||Published - 2013|
|Name||International Conference on Microelectronics-ICM|