On leakage current temperature characterization using sub-pico-ampere circuit techniques

Recently, a reliable circuit design technique for current mode signal processing down to femto-amperes was reported by B. Linares-Barranco and T. Serrano-Gotarredona (2003). The technique involves logarithmic current splitters for obtaining on-chip sub-pA currents and a special saw-tooth oscillator for current monitoring, while using "source voltage shifting". This way, sub-pA currents can be characterized without driving them off-chip which would require expensive instrumentation with complicated low leakage setups. In this paper we report on characterization of temperature dependence of leakage currents, exploiting these techniques. Currents as low as 0.3fA have been characterized.