Curvature-corrected voltage reference using FGMOS devices

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 by replacing matched resistors with matched transistors. 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 replacing of classical MOS devices by a FGMOS transistor will reduce the circuit area, allowing an important increasing of the circuit accuracy that could be achieved by increasing the current generator complexity. The SPICE simulations confirm the theoretical estimated results, showing very small values of the temperature coefficient.