Superior-Order Curvature-Corrected Voltage Reference Using a Current Generator

摘要

A CMOS voltage reference with a logarithmic curvature-correction will be presented. The first-order compensation is realized using an original OVF (Offset Voltage Follower) block as PTAT voltage generator, with the advantages of reducing the silicon area and of increasing accuracy. The new logarithmic curvature-correction technique will be implemented using an ADA (Asymmetric Differential Amplifier) block for compensating the logarithmic temperature dependent term from the first-order compensated voltage reference. In order to increase the circuit accuracy, an original temperature dependent current generator will be designed for computing the exact type of the implemented curvature-correction. The SPICE simulations confirm the theoretical estimated results, showing very small values of the temperature coefficient. The circuit is implemented in 0.35μm CMOS technology and consumes only 9μA for t - 25 C, being supplied at the minimal supply voltage V_DD = 1 .7V . The temperature coefficient of the reference voltage is 8.5ppm/° C , while the line sensitivity is 0.7m V / V for a supply voltage between 1.7V and 7V.