公开(公告)号：DE69722041D1

公开(公告)日：2003-06-18

申请号：DE69722041

申请日：1997-11-29

Applicant: MICROCHIP TECH INC

Inventor： DARMAWASKITA HARTONO ,  NOLAN B

IPC: G01R27/02 ,  G01R27/26 ,  H03K5/153 ,  H03K5/22

Abstract: A direct sensor interface (DSI) module which allows a microcontroller to directly interface to sensors having at least one of a resistive, capacitive, and/or current source characteristic. The DSI module is coupled directly to a sensor device, which could be a reference resistor, which generates a sensor current. A current mirroring circuit outputs a charging current proportional to the sensor current. A capacitive sensor and/or a capacitive device is coupled to the current mirroring circuit and generates a voltage when charged by the charging current. Using a comparator and a threshold voltage source, the time it takes the capacitive sensor 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.

公开(公告)号：DE69722041T2

公开(公告)日：2004-03-25

申请号：DE69722041

申请日：1997-11-29

Applicant: MICROCHIP TECH INC

Inventor： DARMAWASKITA HARTONO ,  NOLAN B

IPC: G01R27/02 ,  G01R27/26 ,  H03K5/153 ,  H03K5/22

Abstract: A direct sensor interface (DSI) module which allows a microcontroller to directly interface to sensors having at least one of a resistive, capacitive, and/or current source characteristic. The DSI module is coupled directly to a sensor device, which could be a reference resistor, which generates a sensor current. A current mirroring circuit outputs a charging current proportional to the sensor current. A capacitive sensor and/or a capacitive device is coupled to the current mirroring circuit and generates a voltage when charged by the charging current. Using a comparator and a threshold voltage source, the time it takes the capacitive sensor 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.