This paper introduces a low-power integrated temperature sensor based on the temperature coefficient of resistive materials and an original improvement of the traditional Wheatstone bridge called "Active Bridge". The primary purpose of the Active Bridge is to bias an amplifier using the same current as for the sensing resistors to reduce the global power consumption. Open-loop behavior of the sensing cell is first described and modeled. A specific closed-loop architecture based on a current feedback is also studied both analytically and experimentally, as a possible application of the basic cell.