US Patent 7365632 - Carbon nanotube nanofabric thin film resistor with improved temperature independence

http://www.freepatentsonline.com/7365632.html

Certain electronic circuits such as voltage regulators and data converters require a high degree of temperature independence to operate properly. This patent from Nantero teaches how to form thin film resistors formed from carbon nanotube fabrics with a sheet resistance in a range of 1 kohm/square - 1 Mohm/square in which the resistance changes by less than 25 parts per million per degree centigrade which is a factor of 10 better than similar thin film resistors. Claim 1 reads:

1. A resistive element, comprising:

a patterned region of nanofabric with a predefined area and a pre-selected sheet resistance, the nanofabric having a pre-selected temperature coefficient of resistance (TCR); and

first and second electrical contacts contacting the patterned region of nanofabric and in spaced relation to each other, wherein

a total resistance of the resistive element between the first and second electrical contacts is determined by the predefined area of the patterned region of nanofabric, the pre-selected sheet resistance of the patterned region of nanofabric between the first and second electrical contacts, and the pre-selected TCR of the nanofabric, and the spaced relation of the first and second electrical contacts; and

wherein the total resistance of the resistive element is tunable to a pre-selected total resistance.