Self-biased nano-power four-transistor current and voltage reference with a single resistor

A generic nano-power voltage and current reference topology, which takes advantage of the unequal threshold voltage (V-TH) of two MOSFETs in subthreshold region, is developed to provide reliable bias and reference signals for the analogue integrated blocks used in the Internet-of-Things applications. The new architecture is a selfpowered four-transistor topology with a single temperature-insensitive resistor, generating both temperature-independent voltage and current without any operational amplifier or bias network. Instead, the resistor defines the absolute value of the current reference (IREF) which supplies the core devices. The circuit is designed and simulated for a target current reference of 7.50 nA in 0.18 mu m CMOS process, and achieves a worst-case temperature coefficient (TC) of 59.47 ppm/degrees C over a temperature range from -40 to 125 degrees C and 1.8 V voltage supply. The average voltage reference (VREF) is 346 mV, and the worst-case TC of different corners is 21.98 ppm/degrees C. The nominal current consumption is twice the IREF (15 nA) regardless of the supply and temperature, and can be scaled down by reducing the desired current reference.