Sensor Signal Conditioning Circuit
The sensor signal conditioning circuit helps increase the accuracy and resolution of your analog sensor measurements. The circuit consists of a Sallen-Key double pole low pass filter stage and an amplifier stage with adjustable gain. The low pass filter section removes high frequency noise from your analog sensor signal to increase measurement accuracy. The amplifier section allows you to scale your sensor signal voltage range to match the voltage range of the ADC to increase measurement resolution.
The input of the sensor signal conditioning circuit consists of a screw terminal connector for easy connection of low frequency analog sensor signals. The output of the circuit consists of a four pin 2.54mm male header: GND, VCC, OUT, GND. The range for VCC is 1.8V to 5.5V. The circuit is referenced to ground so it can only measure signal level between ground and VCC. The amplifier's gain is determined by a 10kohm adjustable resistor. The gain can be set between 0 and 11, but it is limited by VCC. The circuit is available in three different versions, each with a different cutoff frequency: 159Hz, 482Hz, and 15.9kHz.
You can also purchase just the PCB of the design at a reduced price if you want to build the circuit yourself and customize the component values Use the "form" at checkout if you have any special instructions for your order, for instance you don't want the output pins soldered on to your order. For more information and to watch a video on the sensor signal conditioning circuit refer to the the "Additional Info" section.