The LMH32404-Q1 can be placed in low-power mode by setting EN high, which helps in saving system power. Enabling low-power mode puts the outputs of the internal amplifiers in the LMH32404-Q1, including the differential outputs, in a high-impedance state.

If a system consists of high number of amplifier channels multiplexed to a few ADC channels. Figure 7-4 shows how this device feature can further save board space and cost by eliminating the need for a discrete high-speed multiplexer. The disabled LMH32404-Q1 outputs are high-impedance so multiple LMH32404-Q1 device outputs can be directly shorted to each other. If one LMH32404-Q1 device is enabled and others are disabled, the disabled devices will not load the enabled device. This further makes the LMH32404-Q1 easy to use in photodiode array applications.

When the amplifier is in its low-power mode, the clamp circuitry is still active thereby protecting the TIA input. The ambient light cancellation loop is disabled when the amplifier is placed in low-power mode. When the LMH32404-Q1 is brought out of low-power operation the ambient light cancellation loop requires several time constants to settle. The time constant is based on the 400-kHz cutoff frequency of the loop.