Temperature compensated nanopower voltage/current reference

摘要

An integrated voltage/current reference having substantially reduced temperature and voltage coefficient with simultaneous nanowatt power consumption includes a nanopower voltage/current reference topology having a substantial temperature coefficient and minimal voltage coefficient and augmented with a floating voltage proportional to absolute temperature (PTAT) within a feedback loop to compensate for differentials in &bgr; exponential temperature dependencies of N- Channel and P-Channel MOS devices used within commonly available semiconductor processes. The resulting reference supplies both voltage as well as current references which have greatly reduced temperature coefficients. In addition, the resulting circuit topology generates a voltage reference which has a parabolic temperature coefficient similar to that produced by a conventional bandgap reference. The turnover temperature, or point of zero temperature coefficient, with this new circuit topology can be made to coincide with the turnover temperature of the crystal resonator used within conventional watch crystal oscillator circuits, making this new topology preferable over existing voltage/current reference circuit topologies.