| 摘要 |
PROBLEM TO BE SOLVED: To provide output circuit of an comparator which can prevent an integrated circuit including the comparator output circuit from decreasing in sensitivity and oscillating. SOLUTION: When a signal F1 of a terminal t1 is at H, a transistor (TR) Q3 is turned on to allow a constant current Id to flow from a power source Vcc1 to a resistance R4 via a constant current source 1, a rise in the base potential of a TR Q4 is turned on the TR Q4 to allow a current Io to flow into a resistance R5, and when the output signal of a terminal t2 goes down to L and the signal F1 of the terminal T1 is at L, the TR Q3 is turned off to make currents flow into diodes D1 and D2; and a drop in the base potential of the TR Q4 turns off the TR Q4 and no current flows to the resistance R5, so that the output signal F0 of the terminal t2 becomes H. Consequently, the constant current Id continues to flow into the output circuit irrespective of whether the TR Q3 is on or off, and the applied voltage of a circuit connected to the power source Vcc1 in the integrated circuit will not vary with the internal impedance of the power source Vcc1, thereby preventing oscillation and decrease in sensitivity owing to the sneak path of signals in the integrated circuit.
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