The VGC pin on the MAX2112 follows the convention that lower voltage corresponds to higher gain. The MAX2015 is recommended for its 100 MHz to 3000 MHz frequency range and 75 dB dynamic range. When the received signal is weakest, the MAX2112 requires the highest gain, achieved by the log detector outputting the lowest voltage. As received power increases, the MAX2112’s gain should decrease. Additional analog circuitry will be needed to match the MAX2112 gain control voltage range and slope to the log detector’s voltage versus power characteristic.
