Design of High Performance Load Share Controller IC

To solve uneven distribution of currents and thermal stresses among the power modules in paralleled power systems such as parallel multiple independent power supplies or dc-to-dc modules, a load share controller IC (integrated circuit) was proposed. By using the automatic MSC (master-slave control) technique, the functions necessary to these systems such as even current and thermal stress distribution controlling were achieved. Some new functions including bus short fault protection and Enable function were added to the chip. Simulation results showed that the main expectation for the controller was realized and the current share error at full load was controlled within 1%. In addition, by introducing special start-up control logic, start-up timing of parallel system was obviously improved. The chip was designed in 1.5μm BCD (Bipolar-CMOS-DMOS) technology with an area of 3.6 mm².