An integrable 60-Hz notch filter

Previous configurations of continuous-time 60-Hz notch filters were difficult to integrate on a silicon chip because of the large component values required. A new method based on first-order all-pass networks has been introduced that lends itself more to integration. These networks use time constant multiplication circuitry to achieve large time constants using resistors and capacitors that can be integrated. With this new configuration, a 60-Hz notch filter with notch attenuation exceeding -60 dB can be implemented on a silicon chip.