Tools accurately simulate noise in mixed-signal ASICs

摘要

In some capacitive-sensor applications, the ability to obtain noise levels as low as 10 aF (atofarad) rms in capacitive-sensor-interface ASICs is critical to high performance. To achieve such low noise levels, a mixed-signal-IC developer must have extensive knowledge of sensor characteristics, as well as an ability to accurately model the sensor-IC interface. Developers must use a top-down method, modeling each subblock at a high level to meet overall system-performance requirements. Developers use simulation tools for this task, and the selection of those tools depends on the level in the hierarchy, ensuring an efficient design process.