Simple quadrature oscillator for BIST

A simple quadrature oscillator for the built-in self-test (BIST) of integrated analogue filters is proposed. A new hardware-efficient approach for amplitude control is described, the main assets being: (i) the technique requires little hardware, which makes it very useful for BIST; (ii) the oscillation amplitude is well defined, and (iii) the distortion-level introduced by the amplitude control loop is under the control of the designer.