초록 ▼

A power device circuit comprises a power semiconductor device (MPWR) in series with a load (LD) between a power supply line (1) and a return line (2), and a short-circuit detector (R1, R2, . . . R1', R2', . . . CP) for determining whether the load (LD) is short-circuit. The short-circuit detector ex

A power device circuit comprises a power semiconductor device (MPWR) in series with a load (LD) between a power supply line (1) and a return line (2), and a short-circuit detector (R1, R2, . . . R1', R2', . . . CP) for determining whether the load (LD) is short-circuit. The short-circuit detector examines the distribution of the supply-to-return voltage (Vbg) between the device (MPWR) and the load (LD) by comprising a comparator (CP) which has a first input (+) coupled to a series node (11) between the device and load and a second input (+) from circuit means (R1, R2, . . . , R1', R2', . . . ) coupled between the supply and return lines (1 and 2) to provide the second input (-) with a voltage supply signal (Vbg') which is a predetermined function of the supply-to-return voltage (Vbg). By so comparing the voltage (Vdl) at the series node (11) with the predetermined function of the supply-to-return voltage (Vbg), the detector (SC) provides an output signal (sc) indicating whether or not a short-circuit is present. Preferably pinch-resistors (R1,R2) or a voltage-clamp (ZD) are used with the circuit means (R1, R2, . . ., R1', R2', . . . ), so that the predetermined function of the supply-to-return voltage (Vbg) input to the comparator (CP) varies with the magnitude of the supply-to-return voltage (Vbg). By this means a lower percentage of the supply-to-return voltage (Vbg) can be input at a higher magnitude of the supply-to-return voltage (Vbg) than at a lower magnitude.

대표청구항 ▼

[ What is claimed is:] [1.] A power device circuit comprising a power semiconductor device in series with a load between a power supply line and a return line, and a short-circuit detector for determining whether the load is short-circuit, a supply-to-return voltage being applied between the supply

[ What is claimed is:] [1.] A power device circuit comprising a power semiconductor device in series with a load between a power supply line and a return line, and a short-circuit detector for determining whether the load is short-circuit, a supply-to-return voltage being applied between the supply and return lines in operation of the circuit, wherein the short-circuit detector examines the distribution of the supply-to-return voltage between the device and the load by comprising a comparator which has a first input coupled to a series node between the device and load and a second input from circuit means coupled between the supply and return lines to provide the second input with a voltage supply signal which is a predetermined function of the supply-to-return voltage, and so comparing the voltage at the series node with the predetermined function of the supply-to-return voltage to provide an output signal indicating whether or not a short-circuit is present.