| 摘要 |
PURPOSE:To clip a level at the outside of 1st and 2nd levels by devising this circuit such that a 1st active clip means is operative when a noise higher than the 1st level is inputted and a 2nd active clip means is operative when a noise lower than the 2nd level is inputted. CONSTITUTION:Since a 1st level is set to +5V being a power supply voltage level and a 2nd level is set to 0V, when a noise level inputted from a signal line 3 to a CPU 1 is within the range of 0 to +5V, the CPU 1 is not latched up. A noise limiter consists of an UA clipper 7 and an LA clipper 8, and input terminals 7a, 8a of the clippers 7,8 are connected to a signal line 3 at a point S. Moreover, the UA clipper 7 and the LA clipper 8 are provided respectively with output terminals 7b, 8b and reference input terminals 7c, 8c, and the output terminal 7b of the UA clipper 7 and the input terminal 8c of the LA clipper 8 are connected to ground and the input terminal 7c of the UA clipper 7 and the output terminal 8b of the LA clipper 8 are connected to a power supply line 5. |
