| 摘要 |
PROBLEM TO BE SOLVED: To provide a load drive circuit and its load current setting method capable of operating a charge pump circuit at an optimum boosting rate, with no frequent switching of the boosting rate of the charge pump circuit. SOLUTION: At starting, a control circuit 11 sequentially raises a boosting rate according to a boosting rate control signal Sc until a constant current circuit 18 can supply a load current corresponding to a current set value of a current setting circuit 12 after setting the boosting rate of a charge pump circuit 15 to be a lowest value. The current setting circuit 12, when the first pulse signal of a load current setting signal Sa of continuous pulse signals corresponding to a set current value is inputted, sets the current set value to the maximum one, and sequentially decreases the current set value each time the pulse signal of second or later is inputted. The control circuit 11, when a load current is set by the load current setting signal Sa, performs operation at start-up each time the pulse signal is inputtted. COPYRIGHT: (C)2009,JPO&INPIT
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