High-Pass Filter (RC)

Here's an example of an RC high-pass filter. This circuit allows high-frequency signals to pass while attenuating low-frequency signals. When a DC voltage is applied (a step input), the capacitor acts as an open circuit after it is fully charged, thus blocking the DC signal from the output. The output voltage across the resistor shows a quick spike and then decays to zero.

export default () => (
    <board width={16} height={16} schMaxTraceDistance={5}>
      <voltagesource
        name="V1"
        voltage="5V"
        schX={-4}
        schY={1}
        schRotation={270}
      />
      <capacitor
        name="C1"
        capacitance="10uF"
        footprint="0402"
        schX={-1}
      />
      <resistor
        name="R1"
        resistance="35ohm"
        footprint="0402"
        schX={2}
        schY={1}
        schRotation={270}
      />

      <trace from={".V1 > .pin1"} to={".C1 > .pin1"} />
      <trace from={".C1 > .pin2"} to={".R1 > .pin1"} />
      <trace from={".R1 > .pin2"} to={"net.GND"} />
      <trace from={".V1 > .pin2"} to={"net.GND"} />

      <voltageprobe connectsTo={".V1 > .pin1"} />
      <voltageprobe connectsTo={".R1 > .pin1"} />

      <analogsimulation duration="2.5ms" timePerStep="0.01ms" spiceEngine="ngspice"/>
    </board>
)

The simulation results show the voltage at the input and at the output across R1. The output voltage briefly matches the input and then decays to 0V as the capacitor charges. This demonstrates the "differentiating" behavior of a high-pass filter.