CHARGING OF BOOTSTRAP CAPACITANCE BY LDMOS

摘要

PROBLEM TO BE SOLVED: To ensure low consumption and high immunity to breakdown of an integrated device by sustaining the open state of a switch during the charging period of a bootstrap capacitance and closing the switch when the charging voltage of bootstrap capacitance reaches a reset threshold level. SOLUTION: A switch INT1 interrupt a source node from then first junction of drain of direct bias junction normally present between the source node and a current source connected with the ground potential during the variation phase of a bootstrap capacitance Cboot. When the variable voltage of bootstrap capacitance Cboot reaches a preset threshold level, the switch INT1 is turned off. Furthermore, an inrush current is limited when a parasitic transistor is triggered, in any case, by means of a limit resistor R inserted between the body node of LDMOS structure and the current source connected with the ground potential.