Electronic circuit device for protecting electronic circuits from unwanted removal of ground terminal.

摘要

An electronic circuit device with an external ground terminal (23) used for vehicle AC regulators comprises a detection circuit (26) for detecting that the external ground terminal has been removed from a ground, and a protection circuit for protecting an electronic circuit (22) according to the detected signal of the detection circuit (26). The protection circuit includes a low voltage protection circuit (24) for stopping an operation of an output transistor (18) of the electronic circuit (22), a latch circuit (25) operated by output signals from both the detection circuit (26) and the low voltage protection circuit (24), and an input cut-off circuit (16) for cutting off input signals applied to the electronic device.