The following layout example shows how the FPC202 can be placed underneath a stacked SFP cage, on the opposite side of the PCB. In this example, the FPC202 is being used to control two SFP ports. For reference, a QSFP footprint, which is wider than the SFP footprint, is shown next to the stacked SFP cage. The FPC202 will also fit beneath a stacked QSFP, QSFP-DD, or OSFP cage. In this example, the FPC202 is using two of its GPIO pins to control a TPS2556 power distribution switch which is placed beneath the QSFP cage. Note that there are multiple ways to route the low-speed control signals and I2C signal between the cages and the FPC202. This example uses two inner layers to accomplish this routing.

Figure 8-8 Layout Example