Abstract: A plurality of resistive paths are coupled in parallel to a common node. A high side driver is operable responsive to first control signals to selectively supply current to certain ones of the resistive paths. A low side driver, including a plurality of selectively actuated current sink paths, is provided to sink current from the common node. A control logic circuit actuates a current sink path within the low side driver for each resistive path that is selectively supplied current by the high side driver. A substantially constant low side voltage drop through these sink paths is provided regardless of the number of resistive paths that are supplied current by the high side driver. A switched high side and low side configuration operating in an analogous way is also disclosed.

Abstract: A plurality of resistive paths are coupled in parallel to a common node. A high side driver is operable responsive to first control signals to selectively supply current to certain ones of the resistive paths. A low side driver, including a plurality of selectively actuated current sink paths, is provided to sink current from the common node. A control logic circuit actuates a current sink path within the low side driver for each resistive path that is selectively supplied current by the high side driver. A substantially constant low side voltage drop through these sink paths is provided regardless of the number of resistive paths that are supplied current by the high side driver. A switched high side and low side configuration operating in an analogous way is also disclosed.

Abstract: An LED array includes a plurality of LED segments connected in a common cathode configuration at a common cathode node. A high side driver is operable responsive to segment control signals to selectively supply current to certain LED segments. A low side driver is provided to sink current from the common cathode node. A plurality of selectively actuated current sink paths are provided in each low side driver. A control logic circuit actuates a current sink path within the low side driver for each LED segment that is selectively supplied current by the high side driver. A substantially constant low side voltage drop through these sink paths is provided regardless of the number of LED segments that are supplied current by the high side driver so as to achieve a substantially constant LED segment brightness. A common anode configuration operating in an analogous way is also disclosed.

Abstract: A power supply circuit includes: a switching flyback transformer having a primary winding and a secondary winding; a current transformer having a primary winding and a secondary winding; and a switching transistor have a conduction path and a control terminal. The primary winding of the switching flyback transformer, the primary winding of the current transformer and the conduction path of the switching transistor are coupled together in a series circuit. The switching flyback transformer and the current transformer share a common core. The windings of the switching flyback transformer may be wound around one leg of the common core, while the windings of the current transformer may be wound around a different leg of the common core.

Abstract: A plurality of grids of LED segments form an LED array. Each grid includes a plurality of LED segments connected in a common cathode configuration at a common cathode node. A high side driver is connected to all of the plurality of grids. This high side driver is operable responsive to segment control signals to selectively supply current to certain LED segments. One low side driver is provided for each of the plurality of grids. Each low side driver is responsive to a grid control signal to make a grid selection and sink current from the common cathode node of its corresponding selected grid of LED segments. A plurality of selectively actuated current sink paths are provided in each low side driver. A control logic circuit actuates a current sink path within the low side driver for each LED segment that is selectively supplied current by the high side driver.