The minimum gain of MAX9814 is 20dB/30dB/40dB, while the maximum gain is 40dB/50dB/60dB, which means that the adjustable gain of the AGC is 20dB. For example, when the input signal is 2mV, the AGC can work under maximum gain. However, if the input signal is increased, under such gain the output voltage will reach the threshold, so the gain will be reduced. Yet, when the AGC gain is reduced to 0dB, the amplifier still has at least 20dB and perhaps higher depending on the gain setting. In other words, when the input signal is 50mV, the minimum output should be 500mV. The gain is fixed and it cannot be further reduced to meet the requirement of Vth.