A 4-layer PCB with a solid ground plane and a separate power plane is recommended. Keep the analog and digital grounds separate and connect them at a single point. Use short, wide traces for power and ground connections.
Use a controlled slew rate for the power supply voltage, and ensure that the voltage is within the specified range during hot swap. Also, use a capacitor with a low equivalent series resistance (ESR) to filter the power supply noise.
The maximum cable length depends on the specific application and the type of cable used. However, as a general guideline, the LTC4300A can support cable lengths up to 10 meters (33 feet) for USB 2.0 and 3 meters (10 feet) for USB 3.0.
Use a logic analyzer or oscilloscope to monitor the signals on the bus. Check the power supply voltage and current, and ensure that the device is properly configured and initialized. Also, verify that the device is not overheating or experiencing electrical overstress.
The LTC4300A is rated for operation up to 85°C (185°F). However, the device's performance and reliability may degrade at higher temperatures. Ensure that the device is properly heat-sinked and that the operating temperature is within the specified range.