An analog signal chain for a CMOS active pixel sensor imaging system utilizes, for each amplification stage, a plurality of fixed gain amplifiers instead of a single multi-gain amplifier. The fixed gain amplifier corresponding to the desired gain level is selected and powered on and coupled to the input/output signal paths, while the non-selected fixed gain amplifier(s) are powered off and isolated from the input/output signal paths. Each fixed gain amplifier is operated at a gain bandwidth corresponding to the timing requirements of the imaging system and the gain of the amplifier. Thus, each fixed gain amplifier (other than the one corresponding to the maximum gain of a comparable multi-gain amplifier) operates at a lower level of power consumption than the comparable multi-gain amplifier.