Capacitive Tuning Effects on the Vertical T-coil Broadband ESD Protection Circuit

The vertical T-coil broadband ESD protection circuits have the advantage of very small area. However, due to the process variation and the lack of precise models for the multi-layer helical inductors, the actual performance of the vertical T-coil broadband ESD protection circuit could deviate from the one estimated at the design stage. In this paper, we present an improved circuit with tunability and investigate the effectiveness of the capacitive tuning structure on improving and optimizing the frequency characteristics of the circuit.