Patent ID: 9490823
Filing Date: 2016-11-08
CPC Classification: H03K,H03L

Claim Text:
1. An apparatus comprising: a first differentiator including a first capacitive device, a first resistance device, and a first amplifier, the first amplifier having an output node and an input node, wherein at least one of the first capacitive device and the first resistance device is adjustable; and a second differentiator including a second capacitive device, a second resistance device, and a second amplifier, the second amplifier having an input node and an output node, wherein at least one of the second capacitive device and the second resistance device is adjustable, wherein the input node of the first amplifier is connected to the output node of the second amplifier through the first capacitive device connected in series with the first amplifier and the output node of the first amplifier is connected to the input node of the second amplifier through the second capacitive device connected in series with the second amplifier, wherein the output node of the first differentiator has an output signal with an oscillating frequency that is adjustable by one or more of the adjustable resistance and capacitance devices of the first and the second differentiators and that is independent of the power supply to the first and second differentiators, wherein the first and second resistive devices each has a first node coupled to the input node of the first and second amplifiers, respectively, and wherein a second node of the resistive device of the first differentiator is coupled to the input node of the second differentiator and a second node of the resistive device of the second differentiator is coupled to the input node of the first differentiator.