Patent ID: 6850089

Claim:
An apparatus for high-threshold capacitor-coupling triggering, which receives an input signal at an input terminal of the apparatus, and outputs an output signal at an output terminal of the apparatus according to the input signal, the apparatus comprising: voltage step-down detecting means, with an output terminal, in response to a slow decrease in the voltage level of the input signal, for producing a step-down signal at the output terminal of the voltage step-down detecting means, wherein the step-down signal corresponds to and is delayed against the slow decrease during the slow decrease; a first capacitor, coupled to the output terminal of the voltage step-down detecting means at one terminal of the first capacitor, for coupling the step-down signal with the other terminal of the first capacitor; voltage step-down charging means, having an input terminal coupled to the other terminal of the first capacitor, having an output terminal coupled to the output terminal of the apparatus, and being controlled by the step-down signal from the first capacitor, for charging the output terminal of the apparatus; voltage step-up detecting means, in response to a slow increase in the voltage level of the input signal, for producing a step-up signal corresponding to and being delayed against the slow increase during the slow increase; a second capacitor, coupled to an output terminal of the voltage step-up detecting means at one terminal of the second capacitor, for coupling the step-up signal with the other terminal of the second capacitor; and voltage step-up discharging means, having an input terminal coupled to the other terminal of the second capacitor, having an output terminal coupled to the input terminal of the apparatus, and being controlled by the step-up signal from the second capacitor, for discharging the output terminal of the apparatus.