Power-efficient superior-order curvature corrected voltage reference using CMOS computational circuits

A CMOS voltage reference with a logarithmic curvature-correction is 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 by replacing matched resistors with matched transistors. The new logarithmic curvature-correction technique was 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 was designed for computing the exact type of the implemented curvature-correction. The relatively small complexity of the current squarer allows an important increasing of the circuit accuracy that could be achieved by increasing the current generator complexity. As a result of operating most of MOS transistors in weak inversion, the original proposed voltage reference could be valuable for low-power applications.