Dynamically controlled auto-ranging current sense circuit

A method for sensing a load current, comprising:

• generating, by a sense transistor, a sensing current, the sense transistor coupled to a main transistor that provides the load current, the sensing current proportional to the load current;
• providing, by a driver, a continuous bias voltage to the sense transistor and the main transistor to control the load current;
• generating, by a sense resistor, a sense voltage;
• monitoring a voltage at an output voltage of the main transistor;
• and
• generating a control signal for controlling at least one of a gain ratio of the sense transistor, a resistance of the sense resistor, and the bias voltage generated by the driver, wherein the control signal is generated by:
• modifying the value of the control signal in a first direction responsive to the output voltage of the main transistor becoming smaller than a first threshold voltage, and
• modifying the value of the control signal in a second direction responsive to the output voltage of the main transistor becoming larger than a second threshold voltage, the second direction opposite to the first direction.

A controller circuit for controlling a sensing circuit, the sensing circuit for sensing an output of a main transistor, the controller circuit comprising:

• a first comparator configured to generate a first counter signal responsive to an output voltage of the main transistor becoming smaller than a first threshold voltage;
• a second comparator configured to generate a second counter signal responsive to the output voltage of the main transistor becoming larger than a second threshold voltage;
• and
• a counter having a first input coupled to an output of the first comparator and a second input coupled to an output of the second comparator, the counter configured to modify a value of a control signal in a first direction responsive receiving the first counter signal and configured to modify the value of the control signal in a second direction responsive receiving the second counter signal, the second direction opposite to the first direction, the control signal for controlling at least one of a gain ratio of a sense transistor of the sensing circuit, a resistance of a sense resistor of the sensing circuit, and a continuous bias voltage generated by a driver of the sensing circuit.