SBOS710D October 2014 – February 2018 LMH5401
Power-supply decoupling is critical to high-frequency performance. Onboard bypass capacitors are used on the LMH5401EVM; however, the most important component of the supply bypassing is provided by the PCB. As shown in Figure 78, there are multiple vias connecting the LMH5401 power planes to the power-supply traces. These vias connect the internal power planes to the LMH5401. VS+ and VS– must be connected to the internal power planes with several square centimeters of continuous plane in the immediate vicinity of the amplifier. The capacitance between these power planes provides the bulk of the high-frequency bypassing for the LMH5401.