A CMOS voltage reference without resistors for ultra-low power applications

A MOSFET-only reference is fabricated in 0.18 mum CMOS technology. It uses stacked transistors biased in weak inversion to shift the produced negative temperature coefficient to relax the requirement for the weighting gain. The temperature dependence and the supply sensitivity of the output are 127 ppm/degC and 6 mV/V, respectively. The chip occupies 0.004 mm
²
and consumes less than 40 nW at 0.7 V supply.