SWITCHING CURRENT CONTROL CIRCUIT, LED DIMMER SYSTEM, AND LED ILLUMINATION DEVICE

摘要

Provided is a switching current control circuit which comprises a switching pulse supply circuit, a comparator circuit, an analogue circuit unit, and a digital circuit unit and the like. An A/D converter (2) detects load current in the ON period of a switching pulse as detection current and converts this to digital data. Based on this data, a calculation control circuit (3) calculates a lower-limit value for the detection current, which provides a switching timing from OFF to ON for the switching pulse. A continuous/discontinuous mode is decided based on whether or not this lower-limit value is 0 and above.