Power supply insensitive PTAT voltage generator

摘要

A method and apparatus for generating a voltage that is proportional to an absolute temperature (PTAT voltage). A current generator for generating a current that is proportional to absolute temperature (PTAT current) has an internal resistance and two diodes. The PTAT current is proportional to the resistance, and the temperature coefficient of the PTAT current is defined by the ratio of diode current densities. A feedback circuit has a source follower that is connected to the current generator for driving the output node with a regulated PTAT current wherein the PTAT current is mirrored accurately, providing a constant Vref.