CIRCUIT FOR DETECTING SIGNAL OF TWO FEEDING POWER SUPPLIES ON ONE TRANSMISSION LINE

摘要

PROBLEM TO BE SOLVED: To obtain a circuit that has a similar function to that of a known circuit with a simple configuration without the need of a synchronizing signal. ;SOLUTION: The signal detection circuit that constructs a detection signal of a 2-feeding power supplies and one transmission line to be a positive and a negative changes in at least one supply voltage on wiring of the transmission line is provided with a low pass filter 20 that applies a prescribed reference voltage V+ nearly equal to a voltage of a line selected in advance from two lines connected to the two lines of the transmission line at its filter output terminal, a 1st threshold comparator 21 that has a reference input terminal 27 and a threshold input terminal 29 connected respectively to the output terminal 18 of the filter 20 and the pre-selected line in the two lines, and a 2nd threshold comparator 22 that has a reference input terminal 28 and a threshold input terminal 30 respectively connected to the pre-selected line in the two lines and the output terminal of the filter 20. The detection circuit is configured comparatively simply and requires no synchronizing signal for its operation and needs only a very small area for the provision of an integrated circuit.;COPYRIGHT: (C)2000,JPO