Texas Instruments Incorporated
Adaptive power adjustment for current output circuit

Abstract:

A circuit includes an output current circuit that employs a regulated voltage to provide an output voltage to drive a load current through an output load resistor. A load resistance sensor (LRS) senses the resistance of the output load resistor based on the output voltage and the load current. A controller provides a sense voltage control command to set the regulated voltage to an initial sense voltage during a sense mode. The initial sense voltage adjusts the output voltage of the output current circuit and enables the LRS to sense the resistance of the output load resistor at a given setting of the load current. The controller provides a clamp control command based on the sensed resistance of the output load resistor to set the regulated voltage to a fixed regulated voltage during an operation mode. The fixed regulated voltage enables the output current circuit to supply a predetermined maximum load current to the output load resistor at a predetermined minimum setting of the output voltage.