公开(公告)号：EP0955724A1

公开(公告)日：1999-11-10

申请号：EP98830276.6

申请日：1998-05-08

Applicant: STMicroelectronics S.r.l.

Inventor： Chiozzi, Giorgio ,  Marcone, Bruno

IPC: H03F1/52

CPC classification number: H03F1/523

Abstract: A short-circuit protection circuit, particularly for power transistors, whose particularity is the fact that it comprises: first means (11) for mirroring the output current of a power transistor (12) which are parallel-connected to the power transistor, and second mirroring means (13, 14) which are series-connected to the first mirroring means (11) and are adapted to emit a current which is correlated to the current mirrored by the first mirroring means, for comparison with a reference current (Iref); the result of the comparison determining the need to intervene or not on the power transistor (12); and in that it further comprises means (16) for sensing the voltage drop across the power transistor which are parallel-connected to the power transistor and to the first mirroring means (11), in order to adjust minimum and maximum values of the current in output from the power transistor, as a function of the voltage that is present across the transistor.

Abstract translation: 一种特别用于功率晶体管的短路保护电路，其特征在于它包括：用于镜像并联连接到功率晶体管的功率晶体管（12）的输出电流的第一装置（11），和第二 串联连接到第一镜像装置（11）的镜像装置（13,14），并适于发射与第一镜像装置镜像的电流相关的电流，以便与参考电流（Iref）进行比较。 比较结果确定了在功率晶体管（12）上干涉的需要; 并且其还包括用于感测并联连接到功率晶体管和第一镜像装置（11）的功率晶体管两端的电压降的装置（16），以便调整电流的最小值和最大值 作为晶体管两端存在的电压的函数从功率晶体管输出。