Electromagnetic input device and coil detection circuit thereof

The invention provides an electromagnetic input device and a coil detection circuit thereof. The coil detection circuit thereof for the electromagnetic input device including a plurality of first loop coils and second loop coils includes a first detection unit, a second detection unit and a selection unit. One of the first loop coils is an Nth loop coil, and one of the second loop coils is an Mth loop coil. When the selection unit selects the Nth loop coil to emit an electromagnetic signal for each one of the second loop coils, each one of the second loop coils forms a second closed loop for receiving the electromagnetic signal, and the second detection unit detects a second signal. When one of the second loop coils forms an open circuit or short circuit, the second detection unit detects an open-circuit signal or a short-circuit signal.