Trim bit setting of analog filters using wavelet-based supply current analysis

Wavelet transform has the property of resolving signal in both time and frequency unlike Fourier transform. In this work, we show that time-domain information obtained from wavelet analysis of supply current can be used to efficiently trim analog filters. The pole/zero locations in the frequency response of analog filters shift due to change in component values with process variations. Wavelet analysis of supply current can be a promising alternative to test frequency specification of analog filters, since it needs only one test stimulus and is virtually unaffected by transistor threshold variation. Simulation results on two test circuits demonstrate that we can estimate pole/zero shift with less than 3% error.