公开(公告)号：EP0822475A1

公开(公告)日：1998-02-04

申请号：EP96830431.1

申请日：1996-07-31

Applicant: SGS-THOMSON MICROELECTRONICS s.r.l.

Inventor： Borghi, Maria Rosa ,  Magazzu', Antonio

IPC: G05F1/00 ,  H02M3/155

CPC classification number: G05F1/465

Abstract: The invention concerns a method of controlling the charging of a bootstrap capacitance (C BOOT ) incorporated into a switching regulator (2) of a power transistor (M1). The method consists of carrying out, at each switching cycle, a comparison between the voltage value (V CBOOT ) at the bootstrap capacitance (C BOOT ) and a predetermined threshold voltage (Vs), to change the mode of operation of the regulator following said comparison.
More particularly, the control on the transistor (M1) is taken off the regulator (2) when the voltage (V CBOOT ) at the bootstrap capacitance (C BOOT ) is lower than the threshold voltage (Vs), while the transistor (M1) is forced into the "on" state through a full cycle. In this way, the minimum current (I MIN ) to operate the regulator (2) can be minimised.

Abstract translation: 本发明涉及控制掺入到功率晶体管（M1）的开关调节器（2）的自举电容（C BOOT）的充电的方法。 进行，在每个开关周期的方法besteht，在自举电容（C BOOT）的电压值（VCBOOT）和预定的阈值电压（Vs）之间的比较，改变调节器按照所述比较的操作模式。 更具体地，在晶体管（M1）的控制被取出的调节器（2）当在自举电容（C BOOT）上的电压（VCBOOT）大于阈值电压（Vs）降低，而晶体管（M1）被强制 通过将一个完整周期的“开”状​​态。 以这种方式，最小电流（I MIN）来操作调节器（2）可被最小化。