The paper deals with fault isolation in nonlinear analogue circuits with tolerance under an insufficient number of independent voltage measurements. The L1-norm optimisation problem for different scenarios of nonlinear fault diagnosis is formulated with a new fast method being presented. How to solve the L1-norm optimisation problem is discussed and a new neural network-based approach for solving the nonlinear constrained L1-norm optimisation problem is proposed and utilised in locating the most likely faulty elements in nonlinear circuits. The validity of the proposed method is verified and simulation examples are presented.

A new method for fault diagnosis of large-scale analogue circuits based on the class concept is developed in this paper. A large analogue circuit is decomposed into blocks/sub-circuits and the nodes between the blocks are classified into three classes. Only those sub-circuits related to the faulty class need to be, treated. Node classification reduces the scope of search for faults, thus reduced after-test time.' The proposed method is more suitable for real-time testing and can deal with both hard and soft faults. Tolerance effects are taken into account in the method. The class-based fault diagnosis principle and neural network based method are described in some details. Two non-trivial circuit examples are presented, showing that the proposed method is feasible.

According to the principle of fault detect and diagnosis, this paper presents a new technology of data mining to deal. with a lot of data got from fault detection and diagnosis. A method using database technology to solve fault detection and diagnosis is developed.

A general scheme for the VLSI implementation of high-frequency continuous wavelet transform is developed using instantaneous companding technique to get an elegant solution to the problem of maintaining dynamic range and high frequency operation under low power supply voltages. An analogue BiCMOS high-frequency continuous wavelet transform circuit presented in this paper performs a time-frequency decomposition of a high-frequency input signal. The design and implementation of element circuits including voltage-controlled oscillator (VCO), phase-locked loop (PLL) using static and dynamic translinear circuits are also described in detail.

A universal current-mode filter with three inputs using CCII+/-is pressented. This filter which possesses three inputs and one output can generate all biquadratic filtering functions of lowpass, highpass, bandpass, notch and allpass at the output terminate by selecting different input signal combinations of three inputs. The filter has the followng merits: it uses only three CCII+/-, three grounded resistors and three grounded capacitors which makes it not only suitable for integrated circuit implementation, but also independent control of ω0, Q, no matching condition is required. offering multifunction output, and has low passive and active senstivities and cascadability. Its structure is simple than that designed by C. M. Chang and P.C. Chen[7].