Question

how do i select an appropriate commerialally avuable active low pass filter. The amplified transducer singal range is -7.5 V to 7.5V and the highest frequency of intrest is 31khz. this a for and this will be used with the National Instruments model USB 6210 analog-to-digital converter.

please show the calculations needed and a commerialally avuable active low pass filter that would work.

Answer 1

Hello,
          Please find the answer attached as under. Please give a thumbs up rating if you find the answer useful! Have a rocking day ahead!

The most important parameter for selecting a low pass filter is its low cut off frequency. In this case you might have to select a filter with cut off slightly greater than 31KHz, might be around 35KHz. The voltage outputs are typically plus or minus 15 volts for these active low pass filters. Also, since it is a low pass filter, high frequency signals are filtered out, and you will not have any sampling issues with the AD converter.

The UAF42 from TI will suit your purpose. This is a universal filter and you can connect it as a low pass filter according to your design guidelines.