NOVELTY - The circuit (1) has a transmission circuit (Tx1) generating and outputting a transmission signal reflecting a data signal. A reception circuit (Rx1) reproduces the data signal based on a reception signal. An isolation element (ISO1) isolates the transmission circuit from the reception circuit and transmits the transmission signal as the reception signal. A control part (CT1) outputs a stop signal regardless of another data signal supplied from outside to another transmission circuit when the part decides that the data signals reproduced by the reception circuits are same logical level signals.    USE - Semiconductor integrated circuit for a drive apparatus of a power control circuit e.g. industrial inverter equipment and converter equipment. Can also be used for a motor drive apparatus mounted on a two-wheeled electric vehicle, drive apparatus for driving a compressor or motor mounted on a home electrical appliance e.g. air conditioner and refrigerator, a power control apparatus for a high-power home electrical appliance e.g. microwave oven and Induction cooker, a drive apparatus for direct current and alternating current power sources, a dimmer control for lighting equipment, backlight and display, a washing machine, an inverter-controlled florescent lamp, a vacuum cleaner, an LED light, an uninterruptible power supply, a solar power generation system, a cogeneration system, a pump, an LCD for backlight control, a plasma display panel, a machine tool, a robot, a lift, a wind power generation system, a forklift, a gold cart and a fuel cell.    ADVANTAGE - The circuit detects an abnormality that can cause a malfunction in signal transmission through the isolation element, which issues a stop signal to an object to be controlled to turn off an operation upon abnormality detection, thus preventing malfunction of a control target and through-currents from flowing through power transistors, and hence inhibiting reduction in consumption current and securely protecting the power transistors against an over-current state by unfailingly detecting the generation of state without making false determination even if noise is detected in a sense voltage obtained by having a sense current detected with a sense resistor.    DESCRIPTION OF DRAWING(S) - The drawing shows a circuit block diagram of a semiconductor integrated circuit.    Control part (CT1)    Isolation element (ISO1)    Reception circuit (Rx1)    Transmission circuit (Tx1)    Semiconductor integrated circuit (1)