DIRECT SENSOR INTERFACE (DSI) MODULE

摘要

A direct sensor interface (DSI) module which allows a microcontroller to directly interface to sensors having at least one of a resitive, capacitive, and/or current source characteristic. The DSI module (10) is coupled directly to a sensor device (12), which could be a reference resistor (12), which generates a sensor current (Is). A current mirroring circuit (24) outputs a charging current proportional to the sensor current (Is). A capacitive sensor (14) and/or a capacitive device is coupled to the current mirroring circuit (24) and generates a voltage when charged by the charging current. Using a comparator (16) and a threshold voltage source (nVREF), the time it takes the capacitive sensor (14) and/or a capacitive device to ramp up from zero to the threshold voltage can be measured. The charging time is proportional to the sensor reading.