The input connections for DEM-FDA-RUN-EVM depend on several key factors:

• Single-ended or differential input signal
• Configuration and use of multiple feedback filter pads (MFB)
• Setting the desired gain or attenuation

The default configuration of the EVM is to not use the MFB filter configuration, but be in a base FDA configuration with differential inputs. The default gain is 1V/V, also referred to as a buffer or unity-gain setup.

Modifications:

1. To change from differential to single-ended inputs:
   1. Set termination resistor (either R9 or R4) of the active input according to FDA datasheet recommendations
   2. Set termination resistor (either R9 or R4) of the inactive, unused input according to FDA datasheet recommendations
   3. An FDA web calculator is available for investigating single-ended input values.
   4. R9 and R4 will be different values to account for terminating the unused input path
2. To set up MFB Filter:
   1. Calculate your MFB filter values through your preferred method
   2. Use R21, R20, R22, C6, R6, R7, as the input and gain-setting passives for the MFB filter
   3. Use R3, C4, R18 & R10, C7, R24 as the feedback path passives for the MFB filter
   4. Confirm values and proceed with evaluation
3. To change the gain-setting:
   1. Gain is set by RG and RF resistors. For example, on DEM-FDA-RUN-EVM the combination of R3 and R6, as well as the mirrored R10 and R7, set the amplifier gain.
   2. For an FDA the relationship is: Av (Gain) = RF / RG
   3. Please change RF and/or RG to accommodate the desired gain or attenuation