Abstract

MONTOYA-SUAREZ, E  and  ORTEGA-CISNEROS, S. Medición de temperatura usando un VCO integrado en silicio. Rev. mex. fis. [online]. 2011, vol.57, n.6, pp.535-540. ISSN 0035-001X.

The oscillation frequency f₀ of a VCO current-starved has been used for sensing temperature ranging from 20 to 99°C. Since f₀ is directly proportional to the short-circuit current of the basic cell delay (NOT gate), and taking into account that this current, I_SHORT, is directly proportional to the carrier mobility, it is possible to explain how f₀ changes as temperature, T, changes too. This oscillator that was manufactured in a CMOS standard process, N-well, 0.5 μm, 5 V, facilitates the integration of circuitry conditioning, which means the feasibility of integrating the whole sensor system in a chip. Digital circuit measures the frequency f₀ each 53 ms because the measure step is deduced from the linear fitting applied to the f₀ vs. T characteristic.

Keywords : Oscillators; circuits theory; electrical measurements; field effect devices.