Control of multi-string LED array

An illumination system, comprising:

• a system controller integrated circuit (IC), including:
• an internal set of two or more current limiter circuits, wherein each of the internal current limiter circuits is configured to be coupled in series with an associated load, and is further configured to at least partially regulate a current through the associated load;
• an external set of current limiter circuits, wherein each of the external current limiter circuits is coupled in series with a corresponding current limiter circuit of the internal set, and is configured to be coupled in series with the associated load of the corresponding internal current limiter circuit;
• and
• a sense and control unit configured to control a power converter that is configured to supply power to each of the loads based on a signal from one of the current limiter circuits of the internal sets or external sets, and the sense and control unit is further configured to sense voltage differentials across each of the current limiter circuits of the internal set or the external set, and to control the power converter based on a comparison of the smallest of the voltage differentials to a power converter reference signal.

A method of regulating currents through two or more loads, comprising:

• fully or partially regulating a current through a first load with a first current limiter circuit that is in series with the first load;
• fully or partially regulating a current through a second load with a second current limiter circuit that is in series with the second load;
• partially regulating the current through the first load with a third current limiter circuit that is in series with both the first load and the first current limiter circuit if either of the first or second current limiter circuits is partially regulating the current through either the first or the second load;
• and
• partially regulating the current through the second load with a fourth current limiter circuit that is in series with both the second load and the second current limiter circuit if either of the first or second current limiter circuits is partially regulating the current through either the first or the second load;
• sensing voltage differentials across the first current limiter circuit and the second current limiter circuit;
• and
• controlling a power converter based on the comparison of the smallest of the voltage differentials to a power converter reference signal.

An apparatus for regulating currents through two or more loads, comprising:

• a first set of two or more current limiter circuits, wherein each of the current limiter circuits of the first set is configured to be coupled in series with an associated load;
• a second set of current limiter circuits, wherein each of the current limiter circuits of the second set is configured to be coupled in series with a corresponding current limiter circuit of the first set, wherein each current limiter circuit of the first set, in conjunction with the corresponding current limiter circuit of the second set, is further configured to regulate the current through a serially coupled load;
• and
• a sense and control unit configured to control a power converter that is configured to supply power to each of the loads based on a signal from one of the current limiter circuits of the first or second sets, and the sense and control unit is further configured to sense voltage differentials across each of the current limiter circuits of the first set in combination with the corresponding current limiter circuit of the second set and to control the power converter based on a comparison of the smallest of the voltage differentials to a power converter reference signal.