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Circuit Configuration - 1 Channel

The following is a simple circuit diagram for a single pressure sensor.​

Circuit diagram with rising ADC



▲ Circuit diagram with rising ADC

Circuit diagram with falling ADC



▲ Circuit diagram with falling ADC

Output value formula:
	Vout = Vin × R2/(R1+R2)
	R1: The resistor closer to Vin in the diagram above. R2: The resistor closer to GND above.

Rising type circuit characteristics

  • Initial state Vout is 0. Vout increases as more pressure is applied.
  • No power consumption when no pressure is applied.
  • Can be configured as a GPIO Wakeup circuit.

Falling type circuit characteristics

  • Initial state Vout is close to ADC maximum (but not at maximum). Vout decreases as pressure is applied.
  • Circuit is electrically more stable.

Graph Slope Variation by Rc Value​

The following applies to rising type circuits.

Example of sensor contact area



▲ Figure: Graph slope by Rc value

  • If the Rc value is too high, most of the ADC resolution is consumed at initial loads.
  • For Marveldex sensors, we recommend setting the Rc value to 0.5K~2Kohm.

Product for finding the appropriate Rc value: 'Pressure Sensor Starter Kit - 4 Channel'

Output Stage Stabilization​

To reduce noise, you can connect a capacitor between the Vout output and ground. (Typically recommended: 1nF~10nF) The higher the capacitor value, the more noise is reduced, but the signal is reflected more slowly, which may make the sensor response feel slower.