Research On Current Mirror Improvement And Temperature Compensation Technique For CMOS Current Controlled Current Conveyor(CCCⅡ)

The paper studies the principle and improvements of CMOS current controlled conveyor. Regardless of the size of the signal, CMOS current controlled conveyor always provides higher voltage gain under wider bandwidth than the corresponding bandwidth operational amplifier and has the power adjustable features.First, the circuit used widely by scholars is the traditional CCCII proposed by Fabre and it consists of translinear loop and the basic current mirror circuit. However, the weakness of the basic current mirror current is low transmission precision, low output impedance and no current negative feedback circuit. Therefore, the paper presents a CMOS current controlled current conveyor based on cascode current mirror. The improved CCCII circuit is constructed by a translinear loop and cascode current mirror. Compared with CCCII based on the basic current mirror, the improved CCCII circuit has the following merits:high output impedance, high current transfer accuracy. Performance principle of the circuits is analyzed and experiment results are given. The results of experiment verify the feasibility of the improved CCCII.Secondly, although CMOS CCCII based on cascode current mirror performs much better than traditional CMOS CCCII, both of CCCII allow the adjustment of the x-terminal intrinsic resistance via a bias current. This resistance is inversely proportional to surface mobility (u) for CMOS technology.This means that the characteristics of the current controlled current conveyor-based circuits will strongly depend on the absolute temperature. Therefore, a temperature compensation technique for CMOS current controlled current conveyor (CCCII) is proposed. It uses a current biasing circuit which has a current that is directly proportional to the absolute temperature and can also be electronically controlled. The HSPICE simulation results through the 0.18μm CMOS technology from TMSC are given here. Furthermore, basic application examples as a current controlled second-order bandpass filter and a floating inductance simulator have been also considered.