The TRF1305-ADC32RFEVM features two common configurations when driving an ADC. On channel B, the configuration is optimized for power consumption, featuring a single TRF1305 RF Amplifier driving the ADC. When enabling averaging, the ADC noise spectral density (NSD) decreases with each averaging setting used. The analog input path in this configuration then comes to dominate the NSD at 4x averaging mode. This is because the noise due to the ADC decreases below the noise due to the single TRF1305.

To demonstrate the alternate configuration, channel A includes two TRF1305s, which are broken out to separate SMA connectors on the EVM. An external power splitter can be used in this configuration to average out the noise coming from the analog input path, which can improve noise performance when compared to a split after the TRF1305. Alternatively, there are provisions on the board to evaluate the performance of an onboard resistive power divider. This scheme is shown in Figure 3-14.

Figure 3-14 Input Comparison