Back to results
US 6,646,446 B2Granted
Method and apparatus for fault detection in a resistive bridge sensor
AssigneeTexas Instruments Incorporated
InventorsThomas R. Maher, David L. Corkum
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeTexas Instruments Incorporated
InventorsThomas R. Maher, David L. Corkum
Estimating the term…
A full Wheatstone bridge sensor has conditioning electronics of an ASIC connected thereto. Two independently controlled diagnostic switches (S1, S2) in the ASIC are commonly connected to one of the bridge output nodes. The first diagnostic switch connects first resistor between the bridge output node and bridge supply voltage and the second diagnostic switch connects a second resistor between the bridge output and bridge ground. The first diagnostic switch closes during a first diagnostic waveform phase and opens during all other phases of operation. The second diagnostic switch closes during a second and third waveform phase and opens during all other phases of operation. The diagnostic waveforms are used to test major signal conditioning and fault reporting paths of the ASIC.
A bridge sensor having a bridge supply voltage connection, a ground connection and at least one output voltage connection and conditioning electronics having an input and an output connected to the sensor connections, first and second switches connected to the input of the conditioning electronics, the first and second switches having a common terminal connected to the output voltage connection of the bridge sensor, the first switch having a normally open terminal connected to a pull-up load which in turn is connected to the bridge supply voltage connection and the second switch having a normally open terminal connected to a pull-down load which in turn is connected to the ground connection.
A method for detecting faults in a resistive bridge sensor having first and second bridge halves, each half having bridge resistors and conditioning electronics connected thereto comprising the following steps:
A method for detecting faults in a resistive bridge sensor having first and second bridge halves, each half having bridge resistors and conditioning electronics connected thereto comprising the following steps
A sensor having a supply voltage connection, a ground connection and at least one output connection and conditioning electronics having at least one output and at least one input connection to the sensor, first and second normally open switches connected to the at least one input connection of the conditioning electronics, the first switch being connected to a sensor output connection and a first load, and the second switch being connected to a sensor output connection and a second load, the first load being connected between the first switch and a voltage supply and the second load being connected between the second switch and a voltage supply.
Dependencies are inferred from the claim text.