Semiconductor filter circuit and method

摘要

A filter circuit ( 10 ) is formed on a semiconductor substrate ( 11 ) formed with a trench ( 40 ) that is lined with a dielectric layer ( 38 ). A conductive material ( 37 ) is disposed in the trench and coupled to a node ( 62 ) to provide a capacitance that modifies a frequency response of an input signal (V_IN) to produce a filtered signal (V_OUT). An electrostatic discharge device includes an inductor ( 74 ) coupled to back to back diodes ( 17, 18 ) formed in the substrate to avalanche when a voltage on the node reaches a predetermined magnitude.