LED-switching controller and LED-switching control method

摘要

An LED terminal monitoring circuit detects an LED at the lowest potential among a plurality of parallel-connected LEDs. An analog signal selecting circuit gives a signal indicating the voltage of the detected LED to a boosting circuit. The boosting circuit performs a boosting operation on the basis of the condition of the detected LED at the lowest voltage and, consequently, a voltage sufficient for driving the LEDs in a current-control mode can be applied to all the LEDs. Signal lines not connected to LEDs are excluded from objects of a LED-switching control operation.