Abstract: A package with a laminate substrate is disclosed. The laminate substrate includes a first layer with a first terminal and a second terminal. The laminate substrate also includes a second layer with a conductive element. The laminate substrate further includes a first via and a second via that electrically connect the first terminal to the conductive element and the second terminal to the conductive element, respectively. The package can include a die mounted on and electrically connected to the laminate substrate.

Abstract: A package with a laminate substrate is disclosed. The laminate substrate includes a first layer with a first terminal and a second terminal. The laminate substrate also includes a second layer with a conductive element. The laminate substrate further includes a first via and a second via that electrically connect the first terminal to the conductive element and the second terminal to the conductive element, respectively. The package can include a die mounted on and electrically connected to the laminate substrate.

Abstract: A drive system for multiple LED strings powered by a common line voltage. Current control circuits are connected in series with respective LED strings; each current control circuit includes a drive transistor (typically a FET) which causes a desired LED string current to be conducted. In one embodiment, the current conducted by a selected one of the LED strings is controlled by the line voltage regulation loop, while the currents conducted by the remaining LED strings are controlled by respective local current loops, thus avoiding conflicts between the local current and line voltage regulation loops. The LED string to be current regulated by the line voltage regulation loop can be determined by a variety of criteria, such as the current control circuit having the maximum FET gate voltage, the minimum FET source voltage, the minimum FET drain voltage, the maximum FET gate-source voltage, or the minimum FET drain-source voltage.

Abstract: A LED drive system for controlling an off-chip power supply enables the power supply function to be located ‘off-chip’—i.e., on an IC which is separate from the IC containing the other LED drive system components. The off-chip supply provides a common line voltage for LED strings connected in series with respective current sink circuits at respective junctions, in response to a signal applied to a control input. The system includes a ‘minimum’ circuit which outputs the least of the voltages at the junctions, and an I/O pin which receives a signal that varies with the output of the minimum circuit. When the external supply's control input is coupled to the system's I/O pin, the present system controls the output of the external power supply as needed to provide a desired common line voltage.

Abstract: A LED drive system for controlling an off-chip power supply enables the power supply function to be located ‘off-chip’—i.e., on an IC which is separate from the IC containing the other LED drive system components. The off-chip supply provides a common line voltage for LED strings connected in series with respective current sink circuits at respective junctions, in response to a signal applied to a control input. The system includes a ‘minimum’ circuit which outputs the least of the voltages at the junctions, and an I/O pin which receives a signal that varies with the output of the minimum circuit. When the external supply's control input is coupled to the system's I/O pin, the present system controls the output of the external power supply as needed to provide a desired common line voltage.

Abstract: A LED current control system for use with an LED drive system which includes LED strings connected in series with respective current sink circuits, each of which causes a current to be conducted by the LED string to which it is connected. The drive system includes 3 or more ‘dimming’ inputs with which the LED string currents can be adjusted. The LED current control system comprises at least one minimum circuit which receives two or more dimming inputs and produces an output which is proportional to the lesser of the inputs, a multiplier circuit which receives the outputs of the minimum circuits and at least one other dimming input and produces an output ILED which is proportional to the product of the received signals, and a sink control circuit which receives ILED and controls the current sink circuits such that the string currents vary with ILED.

Abstract: A multi-string LED drive system for multiple LED strings powered by a common line voltage. A plurality of current control circuits are connected in series with respective LED strings, each of which includes a transistor which causes a desired LED string current to be conducted when a sufficient voltage is applied to the transistor's gate. A “maximum” circuit receives each of the gate voltages at respective inputs and outputs a voltage which is proportional to the greatest of the received voltages. A line regulator circuit receives the output of the maximum circuit and a signal which represents a target gate voltage at respective inputs and generates the common line voltage such that the highest of the gate voltages is approximately equal to the target gate voltage, such that system power efficiency is optimized in cases of imbalance between LED string voltage drops and/or sink device characteristics.

Abstract: A line voltage control circuit for use with a multi-string LED drive system which provides a common line voltage for multiple LED strings that are connected to respective current sink circuits at respective junctions. An error amplifier receives the minimum junction voltage and a reference ‘desired junction voltage’ at respective inputs, and a voltage regulator outputs the line voltage in response to a voltage applied to a feedback input. A comparator toggles an output when the maximum junction voltage (Vmax) exceeds a reference limit (Vlimit). A multiplexer receives the error amplifier output and a fixed voltage at respective inputs and provides one of the signals to the regulator's feedback input in response to the comparator output. When Vmax>Vlimit, the fixed voltage is provided to the feedback input and the line voltage is reduced, thereby protecting low voltage current sinks from potentially damaging high voltages.

Abstract: A multi-string LED drive system for multiple LED strings powered by a common line voltage. A plurality of current control circuits are connected in series with respective LED strings, each of which includes a transistor which causes a desired LED string current to be conducted when a sufficient voltage is applied to the transistor's gate. A “maximum” circuit receives each of the gate voltages at respective inputs and outputs a voltage which is proportional to the greatest of the received voltages. A line regulator circuit receives the output of the maximum circuit and a signal which represents a target gate voltage at respective inputs and generates the common line voltage such that the highest of the gate voltages is approximately equal to the target gate voltage, such that system power efficiency is optimized in cases of imbalance between LED string voltage drops and/or sink device characteristics.

Abstract: A drive system for multiple LED strings powered by a common line voltage. Current control circuits are connected in series with respective LED strings; each current control circuit includes a drive transistor (typically a FET) which causes a desired LED string current to be conducted. In one embodiment, the current conducted by a selected one of the LED strings is controlled by the line voltage regulation loop, while the currents conducted by the remaining LED strings are controlled by respective local current loops, thus avoiding conflicts between the local current and line voltage regulation loops. The LED string to be current regulated by the line voltage regulation loop can be determined by a variety of criteria, such as the current control circuit having the maximum FET gate voltage, the minimum FET source voltage, the minimum FET drain voltage, the maximum FET gate-source voltage, or the minimum FET drain-source voltage.

Abstract: A LED drive system for controlling an off-chip power supply enables the power supply function to be located ‘off-chip’—i.e., on an IC which is separate from the IC containing the other LED drive system components. The off-chip supply provides a common line voltage for LED strings connected in series with respective current sink circuits at respective junctions, in response to a signal applied to a control input. The system includes a ‘minimum’ circuit which outputs the least of the voltages at the junctions, and an I/O pin which receives a signal that varies with the output of the minimum circuit. When the external supply's control input is coupled to the system's I/O pin, the present system controls the output of the external power supply as needed to provide a desired common line voltage.

Abstract: A line voltage control circuit for use with a multi-string LED drive system which provides a common line voltage for multiple LED strings that are connected to respective current sink circuits at respective junctions. An error amplifier receives the minimum junction voltage and a reference ‘desired junction voltage’ at respective inputs, and a voltage regulator outputs the line voltage in response to a voltage applied to a feedback input. A comparator toggles an output when the maximum junction voltage (Vmax) exceeds a reference limit (Vlimit). A multiplexer receives the error amplifier output and a fixed voltage at respective inputs and provides one of the signals to the regulator's feedback input in response to the comparator output. When Vmax>Vlimit, the fixed voltage is provided to the feedback input and the line voltage is reduced, thereby protecting low voltage current sinks from potentially damaging high voltages.