LAUSR

A PVT compensated sub-µA current reference is proposed in this paper. It is based on the summation of a proportional to absolute temperature (PTAT) current with a complementary to absolute temperature current. The current generators are realized using the subthreshold beta multipliers. The PTAT current generator of the proposed current reference behaves always as PTAT independent of transistor sizing. The process compensation technique is based on the concept of an inverse process dependency between $$\beta \left( { = \mu C_{OX} {W \mathord{\left/ {\vphantom {W L}} \right. \kern-0pt} L}} \right)$$β=μCOXW/L and the threshold voltage $$V_{TH}$$VTH of the MOS transistor at any process corner. A current reference of 100 nA is implemented in CMOS 0.18 µm technology and studied through simulation. The proposed circuit has a temperature coefficient of 335 ppm/°C in the temperature range of 0–100 °C. It provides a low process variation of ± 2.1% and a lower line sensitivity of 0.093%/V in the supply voltage range of 1.35–3 V. It achieves a better figure of merit of 5.487% compared to the current references reported in the literature.