CURRENT CONTROL CIRCUIT, LED CURRENT CONTROL APPARATUS, AND LIGHT EMITTING APPARATUS

摘要

A counter circuit (6) increments the count value by one in synchronization with a clock pulse received from an oscillating part (4). A lower-order decoder (12) receives a count value from the counter circuit (6) and compares a lower-order bit with a set value (1). Only while the lower-order bit is being coincident with a bit pattern related to the set value (1), the lower-order decoder (12) outputs an H-level. Similarly, an upper-order decoder (14) compares a higher-order bit with a set value (2). Only while the higher-order bit is being coincident with a bit pattern related to the set value (2), the upper-order decoder (14) outputs an H-level. An AND circuit (10) renders a transistor (TR) conductive while both of the lower-order and higher-order decoders (12,14) are outputting the signals of H-levels.