PCB High-Speed Signal Design Guidelines: Agilex™ 5 FPGAs and SoCs

ID 821801
Date 11/18/2024
Public
Document Table of Contents

8.4.1. GTS Transceiver Rail Board Connection and LC Filter Recommendation under Noisy Voltage Regulator

The LC filter recommendation in this section is not required for the GTS transceiver power rails if you meet the voltage regulator (VR) ripple requirement in the following table. Altera recommends using the LTC7151S voltage regulator to meet very tight noise specifications for VCCERT_GTS and VCCEHT_GTS. You can use any other voltage regulators for the GTS transceiver power rails if you meet the voltage regulator ripple specifications by selecting a proper voltage regulator. If you do not meet the VR ripple specification in the following table by using a noisy voltage regulator, Altera recommends using the LC filters in this chapter to block the high noise. Implement one set of LC filters for each tile on the FPGA.

Table 31.  Maximum Ripple Requirements for the GTS Transceiver Analog Power Rails
Power Rail Maximum Ripple (mVp-p)
VCCERT_GTS 5
VCCEHT_GTS 7
Figure 83. Filter Recommendation for VCCEHT_GTS