Temperature sensor circuits

Abstract

The disclosure relates to a temperature sensor circuit comprising: a PTAT voltage circuit; a reference current source; a capacitor; a reset switch connected across the capacitor; a comparator configured to compare a voltage across the capacitor to the PTAT voltage and provide a comparator output; a counter circuit configured to increment or decrement an output word depending on the comparator output (U/D), and repeatedly perform the sequential steps of: i) providing a reset signal to momentarily close the reset switch to discharge the capacitor; ii) counting a number of clock cycles corresponding to the output word while the capacitor is charged by the reference current source; and iii) incrementing or decrementing the output word depending on the comparator output, wherein, after repeating the sequential steps, the output word converges to a value corresponding to a temperature of the PTAT voltage circuit.