A Resistorless CMOS Voltage Reference Based on Mutual Compensation of $V_{T}$ and $V_{\rm TH}$

A novel temperature-stable nonbandgap voltage reference without resistors is presented in this brief, which is compatible with standard digital CMOS technology. Two linear-temperature terms, i.e., thermal voltage V_T and threshold voltage V_TH, are utilized to realize a low-temperature-dependent voltage reference with a significant reduction of nonlinear temperature terms. A self-biased threshold-voltage extractor circuit without any resistor is used to obtain the V_TH and bias currents of the whole circuit. Based on ratioed transistors biased in a strong inversion region and the inverse-function technique, a temperature-insensitive gain can be applied to the proportional-to-absolute temperature term in the reference, and a weighted sum of V_T and V_TH is achieved. Experimental results of the proposed voltage reference implemented with a 0.35- μm CMOS process demonstrate that the output of voltage reference is 905.5 mV, a temperature coefficient of 14.8 ppm/°C with a temperature range of 0°C-100 ^°C is obtained at a 3.3-V power supply, and a power-supply noise attenuation of 61 dB is achieved without any filtering capacitor while dissipating a maximum supply current of 65 μA. The active area is 100 μm ×100 μm.