Temperature sensing circuitry for an Implantable Medical Device (IMD) is disclosed that can be integrated into integrated circuitry in the IMD and draws very little power, thus enabling continuous temperature monitoring without undue battery depletion. Temperature sensor and threshold setting circuitry produces analog voltage signals indicative of a sensed temperature and at least one temperature threshold. Such circuitry employs a Ptat current reference stage and additional stages, which stages contains resistances that are set based on the desired temperature threshold(s) and to set the voltage range of the sensed temperature. These analog voltages are received at temperature threshold detection circuitry, which produces digital signal(s) indicating whether the sensed temperature has passed the temperature threshold(s). The digital signal(s) are then provided to digital circuitry in the IMD, where they can be stored as a function of time for later review, or used to immediately to control IMD operation.
